Data recording method, data recording device, data recording medium, data reproduction method, and data reproduction device

ABSTRACT

In write-once media, there occurs wasted recording space at the time of update of an index file for AV file management. In view of this, a new index file is generated at the time of update, and thumbnail image data in an existing index file is referred to, whereby the wasted space is reduced, At the same time, attribute information is stored in the new index file, whereby high-speed access to minimum information required can be realized.

TECHNICAL FIELD

The present invention relates to a data recording method, data recordingdevice, data recording medium, data reproduction method, and datareproduction device, concerning recording video or audio data to arandom-access storage medium such as a hard disk and an optical disk.

BACKGROUND ART

Digital video recording/reproducing devices (hereinafter, video diskrecorder) adopting disks as media have become popular. A recordingformat for such devices is often the QuickTime® file format or the AVI(Audio Video Interleave) file format, in consideration of compatibilitywith PCs (personal computers).

Japanese Laid-Open Patent Application No. 2001-84705 (Tokukai2001-84705; published on Mar. 30, 2001) discloses a method for managingcontents in a disk when the above-mentioned file format for PCs isadopted. Referring to FIG. 60, an outline of this method is given. Files301 through 303 of a disk 305 correspond to respective scenes or shotsbeing recorded, and each of these files is one QuickTime file(hereinafter, QuickTime movie file).

An index file 300 stores a table of data in the disk 305. There areentries corresponding to the respective QuickTime movie files. Eachentry stores sets of reduced image data 311 through 313 representingrespective scenes, and the names of files including these scenes.

To display an index to the user, miniature images 321 through 323produced by decoding the sets of miniature image data 311 through 313 inthe entry are caused to appear on a contents selection screen 307. Theuser then selects a file that he/she wants to reproduce or edit, fromthese miniature images on the contents selection screen 307. When, forinstance, the user selects the miniature image 323 and instructs thereproduction of the same, a file 303 including the contentscorresponding to the miniature image 323 is acquired and thereproduction of the contents in the file 303 starts.

The index file 300 includes (i) pointers to respective files storing thecontents of the disk 305 and (ii) sets of miniature image data. Thus,the contents selection screen 307 can be shown only by reading out theindex file 300 from the disk 305, so that the time required for causingthe index display (contents selection screen) to appear on the screen isshort. As the contents selection screen 307 is frequently called, thisreduction of the time greatly lighten the frustration of the user.

In recent years, the use of write-once optical disks has increased at afaster rate. A typical example of the write-once optical disks is CD-R.Also, DVD-R has dropped in price and become increasingly common. In thesituation where the foregoing index file is applied to these write-onceoptical disk, the following problem arises.

The index file is a file having a property of increasing its size withuse. In write-once disks, additional recording to a once-recorded fieldis impossible. In dealing with a file increasing its size with use, likeindex file, it is difficult to use the file without a wasted storagespace. For example, if a new index file is additionally written eachtime addition, deletion, change, or the other of an entry occurs withrespect to the index file, a large amount of wasted storage space iscaused.

The present invention has been attained in view of the above problem,and an object of the present invention is to provide a data recordingmethod which can reduce a wasted storage space in a write-once storagemedium.

DISCLOSURE OF INVENTION

A data recording method of the present invention is a recording methodfor recording a set of first data, a set of second data, and a set ofthird data on a recording medium, the set of first data including setsof fourth data, the set of third data including sets of informationregarding the respective sets of fourth data.

In a data recording method of the present invention, the set of seconddata may have zero or more sets of data which are same as the sets offourth data.

In a data recording method of the present invention, whether or not theset of second data includes the same data as the set of fourth data canbe based on attribute of the set of fourth data.

In a data recording method of the present invention, the attribute ofthe set of fourth data may be amount of data.

In a data recording method of the present invention, the attribute ofthe set of fourth data may be hierarchical information.

In a data recording method of the present invention, the attribute ofthe set of fourth data may be priority.

In a data recording method of the present invention, the attribute ofthe set of fourth data may be a time at which data associated with theset of fourth data has been reproduced.

In a data recording method of the present invention, the attribute ofthe set of fourth data may be recorded on the recording medium.

A data recording method of the present invention may be such that theset of first data and the set of second data are managed as one file,and the set of second data including the set of fourth data is made upof an integer number of recording units.

In a data recording method of the present invention, to store the set ofsecond data including the set of fourth data in the integer number ofrecording units, a set of ineffective data may be inserted.

In a data recording method of the present invention, a set of data fornullifying the set of ineffective data is recorded on the recordingmedium.

In a data recording method of the present invention, an insertionposition of the set of ineffective data may be a position at which theset of ineffective data can be inserted.

A data recording method of the present invention may be such that theset of first data includes a front and a rear of the set of fourth data,managed as different files, and relevant information between the filesis recorded on the recording medium.

In a data recording method of the present invention, the set of firstdata may include a set of field reserving data.

A data recording method of the present invention may be such that theset of first data and the set of second data are recorded in differentfiles, and reading control information of the files is recorded on therecording medium.

A data recording method of the present invention may be such that theset of first data and the set of second data are managed as differentfiles, and relevant information between the files is recorded on therecording medium.

In a data recording method of the present invention, the relevantinformation may be represented by a name of the file.

A data recording method of the present invention may be such that theset of third data is a name of a file including the set of fourth databeing available and is positional information inside the file.

In a data recording method of the present invention, the set of thirddata may be information which nullifies the set of fourth data.

In a data recording method of the present invention, the set of thirddata and the set of fourth data may be recorded in different files.

In a data recording method of the present invention, the set of firstdata and the set of second data may be managed as one file.

In a data recording method of the present invention, the set of fourthdata may be recorded in such a manner that its head position of thefourth data is fit to a boundary of recording units.

In a data recording method of the present invention, the set of seconddata may be made up of an integer number of recording units.

In a data recording method of the present invention, the set of thirddata may be positional information of the set of fourth data beingavailable, inside the file.

In a data recording method of the present invention, the set of thirddata may be information which nullifies the set of fourth data.

In a data recording method of the present invention, the set of thirddata may be recorded close on the recording medium.

A data recording method of the present invention may be such that setsof fifth data are recorded on the recording medium, and each of the setsof fourth data is information regarding the set of fifth data.

In a data recording method of the present invention, informationregarding the set of fifth data may be at least one of representativeimage data, representative audio data, title data, and attribute data ofthe set of fifth data.

In a data recording method of the present invention, the recordingmedium may be write-once medium.

In a data recording method of the present invention, the set of thirddata may be recorded close to information indicating a last additionalwriting end position.

In a data recording method of the present invention, the set of seconddata may be additional data of the set of first data.

A data recording device of the present invention is a data recordingdevice including recording means which records a set of first data, aset of second data, and a set of third data on a recording medium, theset of first data including sets of fourth data, the set of third dataincluding sets of information regarding the respective sets of fourthdata.

A data recording medium of the present invention is a recording mediumwhich includes a set of first data, a set of second data, and a set ofthird data recorded thereon, the set of first data including sets offourth data, the set of third data including sets of informationregarding the respective sets of fourth data.

A data reproduction method of the present invention is a datareproduction method for reproducing a set of data in a recording mediumwhich includes a set of first data, a set of second data, and a set ofthird data recorded thereon, the set of first data including sets offourth data, the set of third data being information regarding the setof fourth data, wherein: reproduction control is carried out inaccordance with the set of third data.

A data reproduction device of the present invention is a datareproduction device which reproduces a set of data in a recording mediumwhich includes a set of first data, a set of second data, and a set ofthird data recorded thereon, the set of first data including sets offourth data, the set of third data being information regarding the setof fourth data, the data reproduction device comprising: control meanswhich carries out control in accordance with the set of third data.

According to the present invention, at the time of recording ofadditionally written data, information which managesavailability/invalidity of an existing data is recorded, whereby thereuse of the existing data is possible, thus reducing wasted recordingspace.

Further, according to the present invention, at the time of recording ofadditionally written data, the same data as the existing data isrecorded depending on the attribute of the existing data, whereby it ispossible to read out data having a particular attribute at a high speed,thus improving responses to the user.

For a fuller understanding of the nature and advantages of theinvention, reference should be made to the ensuing detailed descriptiontaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a schematic configuration of avideo disk recorder in an embodiment of the present invention.

FIGS. 2(a)-2(c) are diagrams illustrating relationships betweenmanagement information and an AV stream in a QuickTime file format.

FIG. 3 is a diagram illustrating an outline of Movie atom in theQuickTime file format.

FIG. 4 is a diagram illustrating an outline of Track atom in theQuickTime file format.

FIG. 5 is a diagram illustrating a structure of Track header atom in theQuickTime file format.

FIG. 6 is a diagram illustrating a structure of Media atom in theQuickTime file format.

FIG. 7 is a diagram illustrating a structure of Media information atomin the QuickTime file format.

FIG. 8 is a diagram illustrating an example of data management by Sampletable atom.

FIG. 9 is a diagram illustrating a structure of Sample table atom in theQuickTime file format.

FIG. 10 is a diagram illustrating a structure of Edit atom in theQuickTime file format.

FIGS. 11(a)-(c) are diagrams illustrating an example of reproductionrange specification by Edit atom.

FIG. 12 is a diagram illustrating a structure of User data atom in theQuickTime file format.

FIG. 13 is a diagram illustrating an entire structure of Fragmentedmovie in the QuickTime file format.

FIG. 14 is a diagram illustrating a structure of Movie extends atom inthe QuickTime file format.

FIG. 15 is a diagram illustrating a structure of Track extends atom inthe QuickTime file format.

FIG. 16 is a diagram illustrating a structure of Movie fragment atom inthe QuickTime file format.

FIG. 17 is a diagram illustrating a structure of Movie fragment headeratom in the QuickTime file format.

FIG. 18 is a diagram illustrating a structure of Track fragment atom inthe QuickTime file format.

FIG. 19 is a diagram illustrating a structure of Track fragment headeratom in the QuickTime file format.

FIG. 20 is a diagram illustrating a structure of Track fragment run atomin the QuickTime file format.

FIG. 21 is a diagram illustrating a structure of an AV stream in anembodiment of the present invention.

FIG. 22 is a diagram illustrating a structure of VU in an embodiment ofthe present invention.

FIG. 23 is a diagram illustrating AV stream management structure byQuickTime in an embodiment of the present invention.

FIG. 24 is a block diagram illustrating reference device model in anembodiment of the present invention.

FIGS. 25(a) and 25(b) are diagrams illustrating a relationship ofmanagement information in a UDF.

FIG. 26 is a diagram illustrating a relationship of managementinformation in the UDF in a write-once storage medium.

FIG. 27 is a diagram illustrating a structure of an AV Index file inFirst Embodiment of the present invention.

FIG. 28 is a diagram illustrating a structure of attribute informationin First Embodiment of the present invention.

FIG. 29 is a diagram illustrating a structure of flags in FirstEmbodiment of the present invention.

FIG. 30 is a flowchart illustrating a flow of entire process in FirstEmbodiment of the present invention.

FIG. 31 is a flowchart illustrating a flow of various processes by userinstructions in First Embodiment of the present invention.

FIGS. 32(a) and 32(b) are diagrams illustrating a directory/filestructure before update of an AV Index file and a recorded state on astorage medium, respectively, in First Embodiment of the presentinvention.

FIG. 33 is a diagram illustrating an example of an AV Index managementtable immediately after disk insertion, in First Embodiment of thepresent invention.

FIGS. 34(a) and 34(b) are diagrams illustrating an example of a recordedstate on the storage medium immediately after recording process isperformed, in First Embodiment of the present invention.

FIG. 35 is a diagram illustrating an example of an AV Index managementtable immediately after recording, in First Embodiment of the presentinvention.

FIG. 36 is a diagram illustrating an example of an AV Index managementtable immediately after entry deletion, in First Embodiment of thepresent invention.

FIG. 37 is a diagram illustrating an example of an AV Index managementtable immediately after change of entry data, in First Embodiment of thepresent invention.

FIG. 38 is a flowchart illustrating AV Index file update process inFirst Embodiment of the present invention.

FIG. 39 is a diagram illustrating an example of a recorded state on thestorage medium after update of the AV Index file in First Embodiment ofthe present invention.

FIG. 40 is a flowchart illustrating AV Index file reading process inFirst Embodiment of the present invention.

FIG. 41 is a diagram illustrating a second structure of attributeinformation in First Embodiment of the present invention.

FIG. 42 is a diagram illustrating a structure of additional managementinformation in Second Embodiment of the present invention.

FIG. 43 is a flowchart illustrating AV Index file update process inSecond Embodiment of the present invention.

FIG. 44 is a diagram illustrating an example of a recorded state on thestorage medium after update of the AV Index file in Second Embodiment ofthe present invention.

FIGS. 45(a) and 45(b) are diagrams illustrating an example of a recordedstate on the storage medium before and after merge of the AV Index filein Second Embodiment of the present invention.

FIG. 46 is a flowchart illustrating AV Index file reading process inSecond Embodiment of the present invention.

FIG. 47 is a diagram illustrating a second structure of flags in SecondEmbodiment of the present invention.

FIG. 48 is a diagram illustrating a structure of the AV Index file inThird Embodiment of the present invention.

FIG. 49 is a diagram illustrating an example of a recorded state on thestorage medium before update of the AV Index file in Third Embodiment ofthe present invention.

FIG. 50 is a flowchart illustrating AV Index file update process inThird Embodiment of the present invention.

FIGS. 51(a) and 51(b) are diagrams illustrating an example of a recordedstate on the storage medium after update of the AV Index file in ThirdEmbodiment of the present invention.

FIG. 52 is a flowchart illustrating AV Index file reading process inThird Embodiment of the present invention.

FIGS. 53(a) and 53(b) are diagrams illustrating AV Index file updateprocess (in the case when the variation in the amount of data of Movieatom is an integer multiple of sector) in Fourth Embodiment of thepresent invention.

FIG. 54 is a diagram illustrating a recorded state on the storage mediumafter update of the AV Index file (in the case when the variation in theamount of data of Movie atom is an integer multiple of sector) in FourthEmbodiment of the present invention.

FIGS. 55(a) and 55(b) are diagrams illustrating AV Index file updateprocess (in the case when the variation in the amount of data of Movieatom is not an integer multiple of sector) in Fourth Embodiment of thepresent invention.

FIG. 56 is a diagram illustrating a recorded state on the storage mediumafter update of the AV Index file (in the case when the variation in theamount of data in Movie atom is not an integer multiple of sector) inFourth Embodiment of the present invention.

FIGS. 57(a) and 57(b) are diagrams illustrating an example of arelationship between the AV Index file and fields in Fourth Embodimentof the present invention.

FIG. 58 is a diagram illustrating an example of a recorded state on thestorage medium after update of the AV Index file by a second updatemethod in Fourth Embodiment of the present invention.

FIGS. 59(a) and 59(b) are diagrams illustrating an example of a recordedstate on the storage medium after update of the AV Index file by a thirdupdate method in Fourth Embodiment of the present invention.

FIG. 60 is a diagram illustrating an index file of a conventional art.

BEST MODE FOR CARRYING OUT THE INVENTION

The following will describe in detail embodiments of the presentinvention with reference to the attached drawings. Arrangements sharedby all embodiments will be described first, and then descriptionsspecific to respective embodiments will be given.

System Configuration

FIG. 1 is a schematic diagram of a vide disk recorder shared by allembodiments of the present invention. This device, as illustrated inFIG. 1, includes a bus 100, host CPU 101, RAM 102, ROM 103, userinterface 104, system clock 105, optical disk 106, pickup 107, ECC(Error Correcting Coding) decoder 108, ECC encoder 109, reproducingbuffer 110, recording/after-recording buffer 111, demultiplexer 112,multiplexer 113, multiplexing buffer 114, audio decoder 115, videodecoder 116, audio encoder 117, and video encoder 118, and other memberswhich are not illustrated in the figure, such as a camera, microphone,speaker, and display.

Note that, the video disk recorder in FIG. 1 is equivalent to “datarecording device (recording device)” or “data reproduction device(reproducing device)” recited in the claims.

The host CPU 101 controls, through the bus 100, the demultiplexer 112,the multiplexer 113, and the pickup 107, the audio decoder 115, thevideo decoder 116, the audio encoder 117, and the video encoder 118(despite the members 115 through 118 are not connected to the bus 100 inFIG. 1).

On the occasion of reproduction, data being read out from the opticaldisk 106 through the pickup 107 are error-corrected by the ECC decoder108 and then temporarily held in the reproducing buffer 110. In responseto a data transmission request from the audio decoder 115 and the videodecoder 116, the host CPU 101 instructs the demultiplexer 112 todistribute sets of data in the reproducing buffer 110 to decodersappropriate to the respective types of data, with reference tomanagement information regarding the data being reproduced.

Note that, the pickup 107, the ECC decoder 108, the reproducing buffer110, the demultiplexer 112, the audio decoder 115, the video decoder116, the host CPU 101, and the RAM 102 constitutes “reproducing means”recited in the claims.

In the meantime, on the occasion of recording, data having beencompressed and encoded by the audio encoder 117 and the video encoder118 is supplied to the multiplexing buffer 114, AV-multiplexed by themultiplexer 113, and then supplied to the recording/after-recordingbuffer 111. The ECC encoder 109 adds an error-correction code to thedata held in the recording/after-recording buffer 111, and then the datais recorded on the optical disk 106 by the pickup 107.

Note that, the pickup 107, the ECC encoder 109, therecording/after-recording buffer 111, the multiplexer 113, themultiplexing buffer 114, the audio encoder 117, the video encoder 118,the host CPU 101, and the RAM 102 constitutes “recording means” recitedin the claims.

Audio data is encoded with the MPEG-1 Layer-II, while video data isencoded with the MPEG-2. The optical disk 106 is a DVD-R that is awrite-once optical disk. One sector is made up of 2048 bytes, and an ECCblock is made up of 16 sectors for the sake of error-correction.

File Format

The following will describe QuickTime file format used as a format forAV stream management in the present invention. The QuickTime file formatis a format for multimedia data management which has been developed byApple Computer Inc., and has been widely used in the PC world.

The QuickTime file format is made up of data including video data andaudio data (also collectively referred to as “media data”) andmanagement information. In the present case, the media data andmanagement information are paired up and referred to as QuickTime movie(“movie” for short). The data and management information being paired upmay be stored in one file or in different files.

When being stored in one file, the media data and management informationare arranged as illustrated in FIG. 2(a). Different types of informationare stored in respective “atoms” which are based on a common structure.The management information is stored in “Movie atom”, while the mediadata is stored in “Movie data atom”. Note that, the managementinformation in the Movie atom includes: a table for identifying arelative location of the media data in the file at a certain time;attribute information of the media data; below-mentioned externalreference information; and so on.

When being stored in different files, the management information andmedia data are arranged as shown in FIG. 2(b). In this case, while themanagement information is stored in the Movie atom, the media data isnot necessarily stored in an atom. This condition is described as theMovie atom “externally refers to” the file storing the media data.

As illustrated in FIG. 2(c), it is possible to externally refer to aplurality of AV stream files. This makes it possible to realize“nonlinear editing”, i.e. “nondestructive editing” which enables theuser to apparently carry out editing without changing the locations ofAV streams.

Now, a format of management information in QuickTime will be describedwith reference to FIGS. 3 through 12. First, “atom”, which is a commoninformation storing format, is described. At the head of an atom, “Atomsize” indicating the size of the atom and “Type” indicating the type ofthe atom always exist. Four characters are given to each Type, e.g.‘moov’ for the Movie atom and ‘mdat’ for the Movie data atom. The Atomsize and Type at the top of the atom are collectively referred to as“atom header”.

Each atom can include another atom. That is, atoms are arrangedhierarchically. FIG. 3 illustrates a structure of the Movie atom. “Movieheader atom” manages overall attribute of the movie managed by the Movieatom. “Track atom” stores therein information concerning tracks such asa video track and an audio track in the movie. “User data atom” is auser-defined atom.

FIG. 4 illustrates a structure of the Track atom. “Track header atom”manages overall attribute of the track. “Edit atom” manages which partof the media data is reproduced at which timing of the movie. “Trackreference atom” manages the relationship between the own track andanother track. “Media atom” manages data such as actual video data andaudio data.

FIG. 5 illustrates a structure of Track header atom. Note that,descriptions are given only to those required for the discussion below.“Flags” is a collection of flags that indicate attributes. A majorexample of such flag include “Track enabled flag”. When this flag is 1,the track having the flag is reproduced. On the other hand, when theflag is 0, the track is not reproduced. “Layer” indicates a spatialpriority of the track having the Layer. When there are a plurality oftracks for displaying an image, a track having a Layer with smallervalue comes in front.

FIG. 6 illustrates a structure of Media atom. “Media header atom”manages overall attribute and the like concerning media data managed bythe Media atom. “Handler reference atom” stores therein informationindicating which decoder decodes media data. “Media information atom”manages attribute information peculiar to each video/audio media data.

FIG. 7 illustrates a structure of Media information atom. “Mediainformation header atom” manages attribute information peculiar to eachvideo/audio media data. “Handler reference atom” has already beendescribed in association with the Media atom. “Data information atom”includes “Data reference atom” which manages the name of a fileincluding media data to which the QuickTime movie refers. “Sample tableatom” manages the size of data, reproduction time, and others.

Next, how the Sample table atom is structured will be described. Beforethe description, a method of managing data in QuickTime will bedescribed with reference to FIG. 8. In QuickTime, a minimum unit of data(e.g. video frame) is termed “sample”. For each track, samples areassigned numbers (sample numbers) beginning from 1, which indicate theorder of reproduction.

Also, in the QuickTime format, the reproduction time and data size ofeach sample are in control. A field in a file, in which samplesbelonging to one track are successively provided in the order ofreproduction, is termed “chunk”. Chunks are also assigned numbersbeginning from 1, which indicate the order of reproduction.

In the QuickTime format, moreover, the address of each chunk, theaddress being counted from the head of the file, and the number ofsamples in each chunk are in control. In accordance with suchinformation, the location of a sample corresponding to a particular timecan be figured out.

FIG. 9 illustrates a structure of the Sample table atom. A Sampledescription atom manages a Data format of each chunk, an Index of thechunk of the file in which the sample is stored, and others. ATime-to-sample atom manages reproduction time of each sample.

“Sync sample atom” manages samples that are ready for being decoded inall the samples. “Sample-to-chunk atom” manages the number of samplesincluded in each chunk. “Sample size atom” manages the size of eachsample. “Chunk offset atom” manages the address of each chunk, theaddress being counted from the head of the file.

“Edit atom”, as illustrated in FIG. 10, includes one “Edit list atom”.This Edit list atom has entries in each of which values of “Trackduration”, “Media time”, and “Media rate” are provided. The number ofentries is specified by “Number of entries”. The entries correspond tofields which are successively reproduced on the track, and the order ofentries correspond to the order of reproduction of the fields.

The Track duration indicates reproduction time of a field on the track,the field being managed by the entry. The Media time indicates thelocation of the head of the filed on the media data. The Media rateindicates the speed of reproducing the field. Note that, when the Mediatime is −1, the reproduction of samples on the track is paused for theTrack duration of the entry. This field is termed “empty edit”.

FIG. 11(a)-(c) illustrates an example illustrating how the Edit list isused. In the present case, it is assumed that the contents of the Editlist atom are as illustrated in FIG. 11(a), and the structure of asample is as illustrated in FIG. 11(b). Also, it is assumed that theTrack duration of the i-th entry is D(i), the Media time of the i-thentry is T(i), and the Media rate of the i-th entry is R(i). Thereproduction of samples is in reality carried out in the orderillustrated in FIG. 11(c). These assumptions are now briefly described.

First, in the entry #1, the Track duration is 13000, the Media time is20000, and the Media rate is 1. Thus, in the field from the head of thetrack to 13000, the field from the time 20000 to the time 33000 in thesample is reproduced. Next, in the entry #2, the Track duration is 5000and the Media time is −1. Thus, in the field from the time 13000 to thetime 18000 in the track, no reproduction is carried out.

At the end, in the entry #3, the Track duration is 10000, the Media timeis 0, and the Media rate is 1. Thus, from the time 18000 to the time28000 of the track, the field from the time 0 to the time 10000 in thesample is reproduced.

FIG. 12 illustrates a structure of User data atom. This atom can storetherein an arbitrary number of sets of original information which arenot defined by the QuickTime format. One set of original information ismanaged by one entry, and one entry is made up of “Size”, “Type”, and“User data”. The Size indicates the sizes of the entry itself, the Typeindicates identification information for distinguishing between the setsof original information, and the User data indicates actual data.

Next, the following will describe “Fragmented Movie” that is a conceptintroduced to respond to power shutdown or others caused duringrecording. The Fragmented movie is a concept introduced in MotionJPEG2000 that is one application of the QuickTime format, and theFragmented movie can manage information equivalent to the foregoingSample table atom for each fragment AV stream. The Motion JPEG2000normally uses the term “box”, instead of “atom”. However, the followingdescription will use the term “atom” for uniformity.

FIG. 13 illustrates overall structure of a QuickTime file in which theFragmented movie is introduced. At the head of the QuickTime file,provided is “Movie atom” that manages information common to the entirefile. Following the Movie atom, “Movie data atom” that stores therein afragment AV stream and “Movie fragment atom” that manages an address,size, reproduction time, and others of each sample making up thefragment AV stream data are provided in an alternating manner. Notethat, the AV stream data may exist in other file, as with a normalQuickTime file.

Recording in this order can minimize damage caused by power shutdownduring recording. The Movie atom includes “Movie extends atom” forindicating that the QuickTime movie is a Fragmented movie. The Movieextends atom stores therein a default value for each track included inthe QuickTime movie.

Further, the Movie fragment atom includes management informationregarding the fragment AV stream managed by the Movie fragment atom. Themanagement information includes: “Movie fragment header atom” whichstores therein information regarding the entire fragment AV streammanaged by the Movie fragment atom; and “Track fragment atom” whichstores therein information regarding each track in the fragment AVstream.

The Track fragment atom includes: “Track fragment header atom” thatstores therein information regarding fragment AV stream belonging to thetrack managed by the Track fragment atom; and “Track fragment run atom”that manages logical successive fields (Track run) making up thefragment AV stream belonging to the track. The following will describeeach of the atoms in detail.

FIG. 14 illustrates a structure of the Movie extends atom. The Movieextends atom, as described previously, has a function of indicating thatthe QuickTime movie including this atom is a Fragmented movie.

FIG. 15 illustrates a structure of “Track extends atom”. The Trackextends atom exists to determine a default value of a sample in eachtrack included in this QuickTime movie. “Track ID” refers to track ID ina track defined in the Movie atom. A field that begins with“default-sample-” determines a default value of “track fragment” managedby this atom.

FIG. 16 illustrates a structure of the Movie fragment atom. The Moviefragment atom is management information sequentially recorded duringrecording. This atom, as described previously, includes the Moviefragment header atom and the Track fragment atom that are atoms whichstore sets of actual information regarding the Movie fragment managed bythe Movie fragment atom.

FIG. 17 illustrates a structure of the Movie fragment header atom. Whatinformation the Movie fragment header atom mainly stores therein is“sequence-number”. The sequence-number indicates the sequence from thehead of the Movie fragment managed by the Movie fragment atom includingthe Movie fragment header atom.

FIG. 18 illustrates a structure of the Track fragment atom. The Trackfragment atom stores therein: the Track fragment header atom and theTrack fragment run atom that are sets of management informationregarding samples of a particular track included in the Movie fragment.

FIG. 19 illustrates a structure of the Track fragment header atom. Thisatom stores therein a default value and others for a sample of aparticular track included in the Movie fragment. “Track-ID” indicatescorrespondence to track ID of a track defined in the Movie atom.“Sample-description-index” is an index number of a sample descriptiontable referenced by a sample managed by this atom. Each field thatbegins with “default-sample” is a default value of a sample managed bythis atom.

FIG. 20 illustrates a structure of the Track fragment run atom. Thisatom stores therein sets of management information of respective samplesand successive fields, termed Track run, managed by the Track fragmentrun atom. “Sample-count” indicates the number of samples included in theTrack run. “Data-offset” indicates an offset value of the Track run from“base-data-offset”. A field that begins with “sample-” stores therein avalue such as reproduction time of a sample managed by the Trackfragment run atom. Note that, when the value is equal to the foregoingdefault value, this filed is omitted, which enables data size reduction.

Structure of AV Stream

The following will describe a structure of an AV stream which is commonto all embodiments of the present invention with reference to FIGS. 21and 22. One AV stream is made up of an integer number of ContinuousUnits (CU). The CU is a unit for sequential recording on the disk. Thelength of the CU is determined in such a manner as to assure seamlessreproduction (images and sounds are reproduced without interruption) andreal-time after-recording (sounds are recorded while the images to whichthe sounds are after-recorded are seamlessly reproduced) in whatevermanner the CUs constituting the AV stream are provided on the disk. Thisdetermination of the length will be described later.

One CU is made up of integer number of Video Units (VU). The VU is aminimum unit that can be reproduced by itself. This allows the VU to bean entry point of the reproduction.

FIG. 22 illustrates a structure of the VU. One VU is made up of: integernumber of GOPs (Group Of Pictures) each storing video data for about onesecond; and integer number of AAUs (Audio Access Units) each storingmain audio data reproduced concurrently with the corresponding videodata.

Note that, the GOP is a unit of video compression under the MPEG-2 videostandard and is made up of a plurality of video frames (typically, about15 frames). The AAU is a unit of audio compression under the MPEG-1Layer-II standard, and is made up of 1152 audio wave sample points. Whena sampling frequency is 48 kHz, a reproduction time per AAU is 0.024second. In the VU, the AAU and the GOP are provided in this order inorder to reduce the delay required for carrying out audio/videosynchronous reproduction.

To realize the reproduction of each VU by itself, “Sequence Header” (SH)is provided at the head of each set of video data in the VU. Thereproduction time of the VU is defined by the multiplication of thenumber of video frames included in the VU by the cycle of the videoframes.

Method of Management AV Stream

A method of managing the AV stream is based on the foregoing QuickTimefile format. FIG. 23 illustrates how the AV stream is managed. In thevideo track, the management is carried out in such a manner that onevideo frame is dealt with as one sample, and a series of GOPs in the VUis dealt with as one chunk. In the main audio track, meanwhile, themanagement is carried out in such a manner that one AAU is dealt with asone sample and a series of AAUs in the VU is dealt with as one chunk.

Method of Determining CU

Next, how the CU is determined is described. According to this method,one device (reference device model) is assumed as a reference, andkeeping this assumption in mind, a unit for sequential recording isdetermined in such a manner as not to interrupt the seamlessreproduction.

First, the reference device model will be described with reference toFIG. 24. The reference device model is made up of: one pickup; ECCencoder/decoder 501 connected to the pickup; a track buffer 502, ademultiplexer 503, an after-recording buffer 504, an audio encoder 509,a video buffer 505, an audio buffer 506, a video decoder 507, and anaudio decoder 508.

It is assumed here that seamless reproduction in the present model isassured on the condition that, at the start of decoding the VU, at leastone VU exists on the track buffer 502. The speed of inputting audioframe data to the ECC encoder 501 and the speed of outputting the datafrom the ECC decoder 501 are both determined as Rs.

Moreover, the maximum period for pausing the reading and recordingcarried out by accessing is determined as Ta. Further, a period requiredfor a short access (about 100 tracks) is determined as Tk. Note that,each of these periods includes a period for seeking, a period forwaiting for the rotation, and a period from the access to the output ofdata which is initially read out from the disk, the data being outputtedfrom the ECC. In the present embodiment, In the present embodiment,Rs=20 Mbps, Ta=1 second, and Tk=0.2 second.

When the reproduction is carried out using the above-described referencedevice model, it is possible to assure that there is no underflow of thetrack buffer 502, if the following condition is met.

Before describing the condition, the definitions of symbols are given asfollows: The i-th successive field constituting the AV stream is C#i,and the reproduction time included in the C#i is Tc(i). Tc(i) is anaggregate of the reproduction times of the VUs whose heads are includedin the C#i. Also, a period of time for accessing from the C#i to theC#i+1 is Ta.

Furthermore, a period of time of reading out VUs corresponding to thereproduction time Tc(i) is Tr(i). With these symbols in mind, thecondition with which the underflow of the track buffer 502 does notoccur is represented by the following formula for an arbitrary C#i,provided that the maximum reading time including the jumping betweendiscrete sets of data is Tr(i).Tc(i)≧Tr(i)+Ta  <Formula 1>

This is because, this formula is a sufficient condition to meet thefollowing sufficient condition for seamless reproduction.Σ_(i) Tc(i)≧Σ_(i)(Tr(i)+Ta)

Substituting Tr(i)=Tc(i)×(Rv+Ra)/Rs for Tr(i) in Formula 1 and solvingthe formula for Tc(i), the following condition of Tc(i), which canassure the seamless reproduction, is obtained.Tc(i)≧(Ta×Rs)/(Rs−Rv−Ra)  <Formula 2>

In other words, the seamless reproduction is assured if the aggregate ofthe VUs whose headers are included in the respective successive fieldsmeets the formula above. On this occasion, it is possible to set alimitation in such a manner as to cause the respective successive fieldsinclude complete groups of VUs in which the total reproduction timesmeet the formula above.

In the automatically-divided movie file, it is also necessary to meetFormula 2. However, the first CU of the first automatically-dividedmovie and the last CU of the last automatically-divided movie do notnecessarily meet Formula 2, because of the following reasons: The firstCU can be compensated by causing the start of the reproduction to belater than the start of reading out data from the storage medium.Meanwhile, regarding the last CU, it is unnecessary to care about thesuccessive reproduction as no data follows this CU. Loosening theconditions with regard to the first and last CUs, it is possible toeffectively utilize free areas which are short.

File System

The following will describe a UDF (Universal Disk Format) which is aformat of a file system adopted in the descriptions of the presentinvention with reference to FIGS. 25(a)-(b) and FIG. 26. FIG. 25(b)illustrates an example of recording a directory/file structureillustrated in FIG. 25(a) using the UDF. An AVDP 602 in FIG. 25(b) andFIG. 26 is short for Anchor Volume Descriptor Pointer, is equivalent toan entry point for looking for management information of the UDF, and isnormally recorded at the 256th sector, the N-th sector, or the N-256thsector (N is maximum logical sector number). A VDS 601 is short forVolume Descriptor Sequence and stores therein management information ona volume which is an area managed by the UDF. Typically, one volumeexists in one disk and includes one partition therein. A FSD 603 isshort for File Set Descriptor, and one FSD exists in the partition.Positional information in the partition is represented by a logicalblock number corresponding to a sector number from the head of thepartition. Note that, one logical block corresponds to one sector.

The FSD 603 includes positional information (composed of a logical blocknumber and the number of logical blocks and termed “extent”) of a FE 604that is a File Entry (FE) of a root directory. The FE manages a group ofextents, and the FE rewrites, adds, and deletes the extents so that thesequence of actual sets of data making up a file can be changed, anddata can be inserted and deleted. The FE 604 manages a field 605 whichstores therein a collection of File Identifier Descriptors (FIDs). TheFile Identifier Descriptor (FID) stores therein names of files anddirectories under the root director, and others. A FID 611 and a FID 612in the field 605 includes sets of positional information of a FE 606 anda FE 608, respectively. The FE 606 and the FE 608 manage file names of afile 621 and a file 622, respectively, and further manages a collectionof extents. The FE 606 manages, as extents, a field 607 and a field 610both of which are fields making up actual data of the file 621. In thepresent case, for access to actual data of the file 621, links may befollowed in the following order: the AVDP 602, the VDS 601, the FSD 603,the FE 604, the FID 611, the FE 606, the field 607 and the field 610.

Next, the following will describe the UDF supporting for a write-oncedisk with reference to FIG. 26. FIG. 26 is different from FIG. 25(b) inthat a VAT (Virtual Allocation Table) 613 and a last additional writingend field 614 are added. The VAT is a translation table of addressesindicating respective FEs, and the use of this table allows a write-oncedisk incapable of rewriting to realize apparent rewriting. The lastadditional writing end field 614 is a field for indicating where theprevious additional writing has ended, and is termed “Border out” forDVD-R. In the case of DVD-R, the VAT is recorded immediately in front ofthe Border out. On the occasion of reproduction, the Border out is firstdetected, and the VAT immediately in front of the Border out is readout, so that a translation table of addresses indicating respective FEsis established on memory, and thus access to an actual FE on the disk iscarried out via the translation table. Therefore, apparent rewriting ofa file can be realized in the following manner: data for update isadditionally written, an extent of the data is added to a FE for a fileto be rewritten so that a new FE is generated, the new FE isadditionally written into the disk, and such a mapping that the FE ofthe file is replaced by the new FE is registered in the VAT. Similarly,addition and deletion of a file can be realized in such a manner that anew FE which manages an extent of collection of FIDs is additionallywritten, and such a mapping that a previous FE is replaced by the new FEis registered in the VAT.

First Embodiment

The following will describe first embodiment of the present inventionwith reference to FIGS. 27 through 41.

Management Information Format

As described above, to manage various types of files (hereinafterreferred to as “AV files”) in a disk, e.g. QuickTime movies and stillimage data, a special QuickTime movie file termed an AV Index file 1740is provided in the disk. FIG. 27 illustrates a structure of the AV Indexfile 1740 in the present embodiment. As with a usual QuickTime moviefile, the AV Index file 1740 is made up of Movie atom 1791 that ismanagement information and Movie data atom 1792 that is actual data.

Note that, the AV file is equivalent to “main data” recited in theclaims, the AV Index file is equivalent to “index data” recited in theclaims.

The AV Index file 1740 manages a plurality of entries, and each AV filein the disk is managed by a corresponding entry.

The Movie atom 1791 is made up of the following four tracks: a Propertytrack 1793 for managing sets of attribute information (attribute data)of the respective entries; a Title track 1794 for managing sets of titlecharacter string data of the respective entries; a Thumbnail track 1795for managing sets of representative image data of the respectiveentries; and an Intro music track 1796 for managing sets ofrepresentative audio data of the respective entries.

The sets of attribute information, title character string data,representative image data, and representative audio data regarding therespective entries are managed as samples in the respective tracks 1793through 1796. Taking the AV file 1741 as an example, the attributeinformation is managed by the sample 1701 on the Property track 1793,the title character string data is managed by the sample 1711 on theTitle track 1794, the representative image data is managed by the sample1721 on the Thumbnail track 1795, and the representative audio data ismanaged by the sample 1731 on the Intro music track 1796. The samplesare coordinated with each other in accordance with the reproductionstart times of the respective samples. That is, it is determined thatsamples which are on different tracks but reproduced in an identicalperiod correspond to the same entry.

The Movie data atom 1792 stores therein the attribute information, titlecharacter string data, representative image data, and representativeaudio data concerning each AV file.

Note that, the attribute information, title character string data,representative image data, and representative audio data are equivalentto “index information” recited in the claims.

A set of the attribute information is structured as illustrated in FIG.28. The fields are arranged as follows. “Version” indicates a version ofthe file format. “Flags” is a collection of different types of flags.“Entry-number” stores an ID of the entry corresponding to the attributeinformation.

“Creation-time” indicates when the entry corresponding to the attributeinformation is generated, while “modification-time” indicates when theentry corresponding to the attribute information is modified. “Duration”indicates a reproduction time of the entry corresponding to theattribute information. “File-identifier” stores, when the entrycorresponding to the attribute information corresponds to a file, a filename of the file therein.

The “flags” is now described with reference to FIG. 29. “Status ofEntry” is flags for recognizing whether the corresponding entry isavailable or invalid.

Other types of data stored in the Movie data atom 1792 are nowdescribed. The representative image data is JPEG-reduced images eachhaving the size of 160×120 pixels, the title character string data istext data, and the representative audio data is data compressed underMPEG-1 Audio Layer-II.

Flow of Entire Process

FIG. 30 illustrates a flow from disk insertion to disk eject orpower-off.

When the optical disk 106 is inserted, management information of a filesystem is first read according to the foregoing sequence (Step 2000).Then, an AV Index file is read from the optical disk 106 to display anindex screen (Step 2001). Next, it is checked whether or not the AVIndex should be recorded on the disk at this timing. The recordingtiming is a timing when the necessity for temporarily recordinginformation regarding the AV Index file on the optical disk 106 of theRAM 102 arises for the disk eject instruction, power-off, or reading ofnew information into the RAM 102 from the optical disk 106. If now isthe recording timing, AV Index recording process in Steps 2003 and 2004is performed. On the other hand, if it is not the recording timing, itis checked whether or not any instruction from the user have beenreceived (Step 2008). If any instruction has been received, variousprocesses (see FIG. 31) are carried out according to the instruction.Upon completion of the processes, index screen display update process isperformed with the foregoing processes taken effect (Step 2019).

Next, steps shown in Steps 2003 through 2007 will be described. First,recording of the AV Index file is carried out based on information onthe RAM 102 (Step 2003), and file and directory information is recorded(Step 2004). Then, it is checked whether or not a trigger of AV Indexrecording is power-off or disk eject (Step 2005). If the trigger ispower-off or disk eject, the VAT is recorded (Step 2006), and the“Border out” that is a field for indicating an additional writing endposition is recorded (Step 2007). In the case of reproduction of thisoptical disk 106, the VAT must be first read out, the “Border out” isinformation for looking for the position of the VAT. Therefore, beforefile reading, a reproduction device always moves its pickup to a radialdirection of an optical disk, finds the last “Border out”, and reads outa VAT immediately in front of the “Border out”. An arrangement of thepresent embodiment in which a field where the content of the latest AVIndex file is recorded is placed close to the “VAT” and “Border out”enables reduction of a period for seeking until the AV Index file isread out. This enables quick views of representative image, title, andothers to the user, resulting in improvement in responses to the user.

Next, the various processes in Step 2009 will be described withreference to FIG. 31. First, it is checked whether or not theinstruction is an instruction for recording (Step 2010), and if it isthe instruction for recording, recording process as will be describedlater is performed (Step 2011). If it is not an instruction forrecording, it is checked whether or not it is an instruction for entrydeletion, i.e. deletion of an already-existing AV file (Step 2012). Ifit is an instruction for entry deletion, an entry deletion process (Step2013) as will be described later is performed. If the instruction isneither the instruction for recording nor the instruction for entrydeletion, it is checked whether or not it is an instruction for changeof any of the representative image data, title character string data,representative audio data, attribute information concerning analready-existing AV file (Step 2014). If so, thumbnail and others changeprocess (Step 2015) as will be described later is performed. If thethumbnail and others change process is not instructed, other process(Step 2016) is performed.

The following is a detailed description of each process. Here, it isassumed that an initial state before the process is started is such thaton the optical disk 106, files have been recorded with a directorystructure illustrated in FIG. 32(a), and the files are arranged on theoptical disk 106, as illustrated in FIG. 32(b). That is, AV files,SHRP0001.MOV, SHRP00002.MOV, and SHRP0003.MOV, are recorded inlocations, AV file 2201, AV file 2202, and AV file 2203, respectively.Further, an AV Index file, AVIF0000.MOV, is recorded in a field of an AVIndex file 2204 in FIG. 32(b), at the head of the AV Index file 2204,Movie atom of the AV Index file is recorded in a field 2211. Further, asto SHRP0001.MOV, attribute information, title character string data, andrepresentative image data are recorded in a field 2212, a field 2215,and a field 2218, respectively. As to SHRP0002.MOV, attributeinformation, title character string data, and representative image dataare recorded in a field 2213, a field 2216, and a field 2219,respectively. As to SHRP0003.MOV, attribute information, title characterstring data, and representative image data are recorded in a filed 2214,a field 2217, and a filed 2220, respectively. As a result of the indexscreen display process described later, a table, illustrated in FIG. 33,for managing information regarding the AV Index file is constructed inthe RAM 102. Here, this table is referred to as “AV Index managementtable”. Each line in this table manages a state of the AV Index whichhas been read out at the time of disk insertion, and update of eachentry after disk insertion. Each line has attribute information, a nameof an AV file managed by each entry, representative image data recordinglocation (name of the AV Index file and address information), andpointer information to representative image data held in another area ofthe RAM 102. Note that, the representative audio data and titlecharacter string data are not shown for simplification of illustration.However, they are also treated in the same way as the representativeimage data and attribute information. Names of the files aresubstantially managed based on full pathnames from the root directory.However, directory names are omitted here for simplification ofillustration.

Recording Process

Recording process in the present embodiment is now described withreference to FIGS. 34(a) and 34(b). When the user instructs recording,the audio encoder 117 and the video encoder 118 are activated to startencoding input data from a camera and microphone not shown in theforegoing encoding scheme. Encoded audio data and video data aremultiplexed by the multiplexer 113 in accordance with the foregoing AVstream format. At the time, a size and reproduction time of GOP, whichwill be necessary for recording Movie atom later, are stored in the RAM102. Further, head image, which has been extracted as representativeimage from input video and has been reduced, is JPEG-encoded to generaterepresentative image data, and the representative image data is held inthe RAM 102. An AV stream, as a result of multiplexing, is recorded onthe optical disk 106 by the pickup 107 by way of therecording/after-recording buffer 111 and the ECC encoder 109. Recordingof the AV stream on the optical disk 106 is performed in the rightdirection from location of 2100 in FIG. 34(a).

In response to an instruction for stopping recording from the user, whenan AV stream which remains in the recording/after-recording buffer 1111is completely recorded on the optical disk 106, the number of bytes ofthe recorded AV stream is stored in the RAM 102, and then Movie atom isrecorded. Recording is started from a sector boundary 2112 asillustrated in FIG. 34(a). Upon completion of recording the Movie atom,Skip atom of suitable size is inserted into a field 2102 so that a rearend of atom header of Movie data atom is located immediately in front ofa next sector boundary 2113. Note that the Skip atom is an atom mainlyused for padding in the QuickTime file format. Then, the atom header ofthe Movie data atom is recorded in a field 2103. To the atom header, asum of the number of bytes of the AV stream stored in the RAM 102 andthe number of bytes of the atom header of the Movie data atom isrecorded, and “mdat” that means Movie data atom is recorded. A the end,an FE is recorded at location of 2104. To the FE, recorded isinformation such that this AV file is read from the head thereof in theorder illustrated in FIG. 34(b).

The following will describe the reason for taking such a recordingstructure. In the QuickTime file format, size in the Movie data atom andcontent of the Movie atom are sets of information having a property ofnot being determined before completion of recording. A usual size of theAV stream is larger than that of the recording/after-recording buffer111, so that the AV stream must be recorded before recording of theMovie atom. At this time, in the case of a rewritable disk, it ispossible to return toward the front location (to the left of the AVstream 2100 in FIG. 34(a)) and record the Movie atom therein. On theother hand, in the case of a write-once disk, recording just to therearward location (to the location right of the AV stream 2100 in FIG.34(a)) is permitted. Therefore, in recording on the optical disk,recording is carried out in the order illustrated in FIG. 34(a), and theFE, management information of the file system, is recorded in such amanner that the file is read in the order illustrated in FIG. 34(b). Inthe present case, for sequential reading of a plurality of successivefields using information of the FE, the size of each successive fields,except for the last successive field, must be an integer multiple ofsector (recording unit). Therefore, the Skip atom 2102 is inserted, andthe size of fields where the Movie atom 2101 and the atom header 2103 ofthe Movie data atom are recorded is adjusted so as to be an integermultiple of a sector. Skip atom can be inserted anywhere to the boundaryof higher-order atoms (e.g. the Movie atom and the Movie data atom), sothat, for example, the Skip atom may be inserted immediately in front ofthe Movie atom, in addition to the boundary between the Movie atom 2101and the Movie data atom 2103. Further, in the present embodiment, theMovie atom and the AV stream are stored in one file. However, needlessto say, they may be recorded in different files as illustrated in FIG.2(b). In this case, an AV stream file and a Movie atom-specific file arerecorded in this order.

At the time when recording is completed, a line given line number 3 inFIG. 35 is added to the AV Index management table on the RAM 102. Thefollowing will describe contents of the line. As to the attributeinformation, “entry-number” stores therein a number which is differentfrom the already-existing numbers. Also, as to AV file name, such a filename whose fifth through eighth numbers are different from those of thealready-existing AV file names in the file system is generated andstored in the AV Index management table. As to the representative imagedata recording location, since nothing is recorded on the optical disk106, “NULL” indicating that nothing is recorded is stored therein. As tothe representative image data pointer, an address, on the RAM 102, ofthe foregoing representative image data generated at the time ofrecording is stored therein.

Entry Deletion Process

Entry deletion process in the present embodiment will be now described.Here, it is assumed that a state of the AV Index management table beforebeing deleted is in the state illustrated in FIG. 35. When the userinstructs entry deletion, a line given line number 4 in FIG. 36 is addedto the AV Index management table on the RAM 102. That is, the added lineis such a line having the same entry-number as that of an entry to bedeleted and having “invalid” in status of entry.

Entry Data Change Process

Entry data change process in the present embodiment will be nowdescribed. Here, it is assumed that a state of the AV Index managementtable before entry data is changed is in the state illustrated in FIG.36. When the user instructs change of the representative image, apost-change image is obtained and stored in the form of JPEG-encodeddata on the RAM 102. Next, a line given line number 5 in FIG. 37 isadded to the AV Index management table on the RAM 102. That is, theadded line is such a line having the same entry-number as that of anentry to be changed representative image and having head address on theRAM 102 storing the foregoing JPEG-encoded data therein, in therepresentative image data pointer. In the present case, to indicate thatwhat is changed is only representative image data, “NO CHANGE”indicating that there occurs no change is stored in the other items.Further, as in the recording process, since nothing is recorded on theoptical disk 106, “NULL” is stored in the representative image datarecording location. Note that, although change of representative imagehas been here described, change of other entry data such asrepresentative audio, title, and attribute information is performed inthe same manner.

AV Index Recording Process

An AV Index file recording process in the present embodiment will bedescribed with reference to FIG. 38. First, on the AV Index managementtable, lines having the same entry-number are unified into a single line(Steps 2401 and 2402). Specifically, if there are lines having the sameentry-number, contents of the line having a lower line number areoverwritten by contents of the line having a higher line number, andthen the line having a higher line number is deleted. In overwriting, asto the item which stores therein “NO CHANGE” that means no change,overwriting of the line having a lower number is not performed. Then, adeleted entry is removed. Specifically, a line having entry-number, inwhich status of entry is “invalid”, is deleted from the AV Indexmanagement table (Step 2403).

Next, Sample table of a newly recorded AV Index file is established onthe RAM 102 (Step 2404). Specifically, the Sample table is establishedin such a manner that data having a small amount and desired to bequickly accessed from the user and device because of its importance forthem, such as attribute information and title character string data, isrecorded in the newly recorded AV Index file, and data less important,such as representative image data and representative audio data (e.g.representative image is ineffective in a device just having displaymeans which displays a character string of one line thereon), except fornewly added data, is made reference to the existing AV Index file.

Whether recording in the newly recorded AV Index file or makingreference to the existing AV Index file is determined in accordance withattribute of each of the sets of data: attribute information, titlecharacter string data, representative image data, and representativeaudio data. As the attribute of this data considered is the amount ofdata, as described above. In addition to the amount of data, hierarchalinformation of the data, priority of the data, a time when the AV filecorresponding to the data has been reproduced are also considered. Sucha data attribute may be recorded on the optical disk 106.

The above process is performed by the host CPU 101 and the RAM 102 as“index data generation means” recited in the claims.

With this arrangement, it is possible to prevent decrease in accessperformance to highly important information while reducing wastedrecording space. Next, Movie atom of the newly recorded AV Index file isrecorded (Step 2405), sets of attribute information and title characterstring of all entries in the AV Index management table are recorded(Step 2406), and at the end, representative image data andrepresentative audio data, which are added newly, are recorded. Whatdata is newly added is judged from whether or not the representativeimage data recording location in the AV Index management table is“NULL”.

Note that, the name of the newly recorded AV Index file is a nameobtained by addition of 1 to a maximum value of values taken fifththrough eighth numbers from the names of the existing AV Index files onthe optical disk 106. For example, in the case where the names of theexisting AV Index files are AVIF0000.MOV through AVIF0100.MOV, the nameof the newly recorded AV Index file is SHRP0101.MOV. With thisarrangement, which is the latest AV Index file can be judged from itsname, and reference to the AV Index files except for the latest AV Indexfile can easily reproduce a previous snapshot (state) in the opticaldisk 106.

Thus, the name of the AV Index file is recorded, as relevant informationamong the AV Index files, on the optical disk 106, whereby it ispossible to easily access to a history of changes made to contents ofrecording on the optical disk 106. Further, serial numbers are partiallyput on the names of the AV Index files, whereby the order of historiescan be grasped easily.

The following will specifically describe a recorded state on the opticaldisk 106 immediately after the above process is performed. Here, it isassumed that before the AV Index file recording process is started,there exists an AV Index management table having contents of FIG. 37 onthe RAM 102. As a result of the AV Index file recording process, a newAV Index file 2242 is generated on the optical disk 106 as illustratedin FIG. 39. In the new AV Index file 2242, as to SHRP0002.MOV 2202 ofwhich representative image data has been changed, attribute information,title character string data, and representative image data are recordedin a field 2232, a field 2235, and a field 2238, respectively. As toSHRP0003.MOV 2203 with nothing changed, attribute information and titlecharacter string data are recorded in a field 2233 and a field 2236,respectively. As to newly registered SHRP0004.MOV 2241, attributeinformation, title character string data, and representative image dataare recorded in a field 2234, a field 2237, and a field 2239,respectively. As to representative image data of SHRP0003.MOV 2203, newrecording is not performed since the representative image data ofSHRP0003.MOV 2203 is referred to the field 2220 in the existing AV Indexfile.

Note that, the AV Index file 2204 is equivalent to “old index data” or“first data” recited in the claims. The AV Index file 2242 is equivalentto “new index data (new index data)” or “second data” recited in theclaims.

Therefore, the first data is already-recorded data, and the second datais newly-recorded data. Recording timing is different between the firstdata and the second data, and they are recorded at a distance from eachother on the storage medium. On the occasion of reproduction, the firstdata is read out in preference to the second data. Also, it can be saidthat the second data is additional data of the first data.

Further, the Movie atom 2231 is equivalent to “third data” recited inthe claims, and entry data included in the AV Index file 2204, such asattribute information, title character string data, representative imagedata, and representative audio data (see FIG. 32), is equivalent to“fourth data” in the claims.

Further, “reference information” or “information regarding fourth data”in the claims are equivalent to any of samples (see FIG. 27) included inthe Movie atom 2231 that is management information.

Further, the AV file is equivalent to “fifth data” in the claims.Therefore, it can be said that the fourth data, such as attributeinformation, title character string data, representative image data, andrepresentative audio data, is data having information regarding thefifth data.

Index File Screen Display Process

The following will describe the index file screen display process in thepresent embodiment with reference to FIG. 40. First, a latest AV Indexfile is opened (Step 2300), Movie atom is read, and the foregoing AVIndex management table is generated on the RAM 102. Incidentally, atthis point, only sets of positional information of various types of datasuch as representative image data have been merely acquired, and thevarious types of data have not been read on the RAM 102 yet (Step 2301).Note that, which AV Index file is the latest one can be judged from thefile name, as described previously. Then, sets of title character stringdata and attribute information of the respective entries are read outand stored in the AV Index management table (Step 2302). Next,scheduling of reading of representative image data and representativeaudio data is performed (Step 2303). That is, a user-specified currentindex display order and the file names of the AV Index files includingsets of data are considered to determine a file opening order such thata time elapsed until the file is displayed is the shortest.Specifically, the file opening order is based on an index screen displayorder and is determined such that the number of times the file is openedis decreased. Next, representative image data and representative audiodata are read out from the currently opened AV Index file (Steps 2304and 2305). After reading of available data, the file is closed (Step2306), the name of the AV Index file to be opened next, having beendetermined in Step 2303, is acquired (Step 2308), the determined AVIndex file is opened if the last file has not read yet (Step 2309), andStep 2304 and subsequent steps are performed.

As described earlier, in the Step 2301, reference to the AV Index filesexcept for the latest AV Index file makes it possible to easilyreproduce a past snapshot (state) in the optical disk 106.

Variations

In the present embodiment, deleted entry and pre-change entry data arenot managed by the latest AV Index file. However, they may be managed bythe latest AV Index file. Specifically, it can be considered that anentry having attribute such as deletion of the existing entry or changeof the existing entry data is defined and added. Alternatively, a tablewhich manages availability/invalidity for each sample may be added andrecorded to the Sample table.

Further, in the present embodiment, for reference to the existing data,external reference function of the QuickTime file format is used;however, the same function can be realized by using a function of a filesystem. For example, a sector including data externally referred in thepresent embodiment is determined as an extent of the latest AV Indexfile, and is referred to from the Movie atom, whereby the same functioncan be realized without using the external reference function of theQuickTime file format. Taking FIG. 39 as an example, the latest AV Indexfile is made up of two extents: (1) a successive sector including fields2231 through 2239; and a successive sector including a field 2220. Withthis arrangement, the AV Index file 2204 and the AV Index file 2242 canbe managed as one file. In the present case, the Movie atom includespositional information of the field 2220 inside the one file. Further,when the file name of the latest AV Index file is identical with thefile name of the previous latest AV Index file, the existing data can bereused without increase in the number of the AV Index files.

Moreover, on the occasion of recording entry data such as representativeimage data, when the head position of the entry data is recorded in sucha manner so as to be aligned with a boundary of the sector, the head ofthe entry data is the head of the extent. This simplifies the foregoingprocess and decreases a rate of including redundant data in the AV Indexfile.

In the present embodiment, sets of entry data such as representativeimage data are stored in the AV Index file. However, only the sets ofentry data may be managed collectively, or the sets of entry data may bemanaged as one file for each type of the entry data. Alternatively, thesets of entry data may be recorded in the AV file so as to be referredto by the AV Index file. With this arrangement, in the AV Index fileupdate process, the entry data can be always referred to a common datafile. This eliminates the need for a process of changing a locationreferred for the entry data.

Furthermore, in the present embodiment, in the latest AV Index file,representative image data or representative audio data included in theexisting AV Index file are not recorded, but is referred to the latestAV Index file. However, even the representative image data orrepresentative audio data included in the existing AV Index file may berecorded in the latest AV Index file so that particular data can be readout from the optical disk 106 at a high speed and the responses to theuser can be improved. As the particular data considered is, for example,representative image data regarding a recorded AV file in a hierarchaldirectory at the lower level. Also, it can be naturally considered thatat a timing of recording the latest AV Index file (at the time of diskeject or power-off), representative image data and representative audiodata regarding a file viewed to the user are recorded in the latest AVIndex file. With this arrangement, at the time of disk eject orpower-off, it is possible to reproduce the previous state (e.g. screendisplay) in a short time.

Whether the representative image data and representative audio data arerecorded in the newly recorded AV Index file or are referred to theexisting AV Index file is determined in accordance with attributes ofthese representative image data and representative audio data. As thisattribute considered is, as described above, hierarchal information ofthe data and a time at which an AV file corresponding to the data hasbeen reproduced.

As illustrated in FIG. 41, it can be considered that in the attributeinformation, “priority” that is a field storing a priority fordisplaying and/or reading is provided, and even when data of a higherpriority is included in the existing AV Index file, the representativeimage data or representative audio data are recorded in the latest AVIndex file, whereby an index display at the disk insertion is called ata high speed and the responses to the user is improved.

Second Embodiment

Second embodiment of the present invention will be described withreference to FIGS. 42 through 47. Second Embodiment is different fromFirst Embodiment in that the latest AV Index file does not includemanagement information regarding data in the existing AV Index file andwasted space caused by duplicate recording of management information isdecreased. The following descriptions focus upon differences from FirstEmbodiment since the present embodiment has a lot in common with FirstEmbodiment.

Management Information Format

A structure of an AV Index file in the present embodiment is the same asthat of the AV Index file in First Embodiment, except that “User dataatom” in “Movie atom” includes “index link atom” illustrated in FIG. 42.The index link atom is information indicating a positional relationshipbetween files when a plurality of AV Index files exist on the disk. Inthis atom, a field “previous” and a field “next” exist. In the presentinvention, only the field previous is used. How to use the fieldprevious will be described later.

Flow of Entire Process

Since the flow from disk insertion to disk eject or power-off in thepresent embodiment is the same as that in First Embodiment, descriptionthereof is omitted.

Recording Process

Since the recording process in the present embodiment is the same asthat in First Embodiment, description thereof is omitted.

Entry Deletion Process

Since the entry deletion process in the present embodiment is the sameas that in First Embodiment, description thereof is omitted.

Entry Data Change Process

Since the entry data change process in the present embodiment is thesame as that in First Embodiment, description thereof is omitted.

AV Index Recording Process

The AV Index recording process in the present embodiment will bedescribed with reference to FIG. 43. First, a process of unifying AVIndex management table on the RAM 102 is performed (Steps 3101 and3102). Specifically, NO CHANGE in any item of a line added afterinsertion of the optical disk 106 shows that the location of real datais recorded in an entry having a line number lower than that of the lineadded after insertion of the optical disk 106, so that a line having thesame entry-number is searched for, and the item of no change iscomplemented by contents of the corresponding item in the searched line.If a line from which the contents are acquired is a line added afterinsertion of the optical disk 106, the line is deleted.

Next, in accordance with information in the AV Index management table,Sample table is established (Step 3103). Specifically, each line addedafter insertion of the optical disk 106 is first determined as oneentry, and for each entry, a sample which manages attribute information,representative image data, representative audio data, and titlecharacter string data is generated.

Then, information is stored in the sample depending on type of the line.As to a line indicating entry deletion, “invalid” is set in “status ofentry” of the attribute information, and size information of the samplewhich manages representative image data, representative audio data, andtitle character string data is set to 0. As to the other lines, a sampleis made up in such a manner that the latest attribute information,representative data, representative audio data, and title characterstring data are recorded in the latest AV Index file. Note that,“invalid” set in the status of entry is information which makes invalidthe entry corresponding to that line. The status of entry is equivalentto “third data” recited in the claims.

Next, Movie atom is recorded (Step 3104), and at the end, attributeinformation, representative data, representative audio data, and titlecharacter string data are recorded. Note that, in the field “previous”in the index link atom of the Movie atom, the file name of the previouslatest AV Index file is stored.

Note that, the name of the newly recorded AV Index file is a nameobtained by addition of 1 to a maximum value of values taken fifththrough eighth numbers from the names of the existing AV Index files onthe optical disk 106.

The following will specifically describe a recorded state of the opticaldisk 106 immediately after the foregoing process. Here, it is assumedthat before the AV Index file recording process is started, there existsan AV Index management table having the contents of FIG. 37 on the RAM102. As a result of the AV Index file recording process, a new AV Indexfile 2242 is generated on the optical disk 106 as illustrated in FIG.44. In the new AV Index file 2242, as to SHRP0002.MOV, attributeinformation, title character string data, and representative image dataare recorded in a filed 2252, a field 2254, and a filed 2256,respectively. As to SHRP0004.MOV, attribute information, title characterstring data, and representative image data are recorded in a field 2253,a field 2255, and a field 2257, respectively.

In First Embodiment, the Movie atom in the latest AV Index file managesinformation regarding all entries existing in the optical disk 106.Therefore, the Movie atom in the latest AV Index file includes duplicateinformation of the Movie atom in the previous AV Index file, and theduplicate information causes wasted storage space by the amount thereof.On the contrary, in the present embodiment, the Movie atom of the latestAV Index file manages only the differences (addition and deletion ofentries, and change of entry data) from the previous AV Index file, sothat the present embodiment has the advantage of less duplicaterecording of management information, as compared to First Embodiment.

AV Index Merge Process

When the foregoing AV Index recording is repeated, a plurality of AVIndex files are recorded in a dispersed manner on the optical disk 106,as illustrated in FIG. 45(a). In the optical disk, it takes time to moveto a reading position, so that increase in the number of times thereading position is changed results in increase of a total reading time.Therefore, repeating the AV Index recording increases a reading time,which could affect responses, such as display of Index screen, andothers. As a method for solving this problem, considered is a method ofmaking close the contents of the plurality of AV Index files beingrecorded in a dispersed manner and recording them. Here, the process ofthis method is referred to as merge process.

The merge process is described using an example. FIG. 45(b) illustratesan example in which the merge process has been carried out, and sets ofentry data, such as attribute information and representative image,included in an AV Index file 3303 and an AV Index file 3304 arecollectively recorded in an AV Index file 3306. Naturally, Movie atomstores therein Sample table for managing those sets of entry data. Thefile name of the AV Index file 3306, as described earlier, is oneobtained by addition of 1 to the fifth through eighth numbers in thename of the previous AV Index file, the AV Index file 3304. In thepresent case, what is stored in the field “previous” of the index linkatom in the User data atom of the Movie atom is the file name of an AVIndex file 3302 that is the immediately preceding AV Index file of an AVIndex file from which the entry data are merged. With this arrangement,during reading of the AV Index files from the latest one to the previousones, reference to the field previous makes it possible to prevent setsof data having been merged from being read again. In addition, the AVIndex file from which the entry data are merged remains, so that afunction of easily reproducing the previous state is not impaired. Notethat, in the present embodiment, the merge process is performedindependently from a normal AV Index recording process. However,needless to say, the merge process may be performed simultaneously withthe normal AV Index recording process. Further, as in First Embodiment,needless to say, entries and entry data to be merged may be selected inaccordance with attributes of entries and entry data.

Thus, information stored in the field “previous” of the index link atomin the User data atom of the Movie atom is information for controllingreading of files, and this information is equivalent to “reading controlinformation” recited in the claims.

Edit-Process Redoing Process

As described above, the AV Index file is recorded at the time of diskeject or power-off, or at an arbitrary timing, so that a previoussnapshot (state) by the recorded AV Index file can be easily reproduced.

Edit operation or other operations performed during a period fromreading of the existing AV Index from the disk to writing of the changedAV Index into the disk can be easily cancelled since the AV Indexmanagement table is on the RAM. Meanwhile, a lower number in the AVIndex file name shows that the AV Index file was generated earlier, sothat it is easy to return to a previous state by the AV Index. It ispossible to identify when the AV Index file was generated, in accordancewith date and time information set in the AV Index file.

In the present case, it is considered to return the latest AV Index fileto a three previous AV Index file, for example. Here, “return” meansthat the contents of the present AV Index management table on the RAMand edit operation managed on the first and second previous AV Indexfiles are all abandoned to return to the three previous AV Index file.This is realized by going, three times, steps back to the previous AVIndex file managed in the field “previous” of the index link atom. Thethree previous AV Index file grasped by the index link atom is read outfrom the disk, and edit operation or other operations is continued withrespect to the three previous AV Index file. On the occasion of actualrecording of the latest AV Index file to the disk, the file name of thethree previous AV Index file is stored in the field “previous” of theindex link atom in the User data atom of the Movie atom.

With this arrangement, on the occasion of reading the AV Index file byreturning from the latest AV Index file to a previous AV Index file,reference to the field “previous” makes it possible to prevent data forwhich edit operation has been cancelled from being read again. Further,the AV Index file for which edit operation has been cancelled stillremains, so that a function of easily reproducing a previous stateincluding the cancelled edit operation is not impaired. Furthermore,what are recorded to cause the three previous AV Index file to be thelatest AV Index file are, as an AV Index file having a file number thatis not used and having the highest file number among AV index files inthe disk, (1) a special AV Index file storing one attribute informationin which 0 (no entry is managed) for the number of samples is recordedto indicate that no available entry is managed or (2) a special AV Indexfile storing one attribute information in which “NULL” is recorded toall fields to indicate that no available entry is managed, and (3) aspecial AV Index file storing the file name of the three previous AVIndex file in the index link atom. This makes it possible to go back tothe three previous AV Index file from the first read AV Index filehaving the highest file number among the AV Index files in the disk.

Index File Screen Display Process

The following will describe the index file screen display process in thepresent embodiment with reference to FIG. 46. First, the latest AV Indexfile is opened (Step 3201), Movie atom is read, and the foregoing AVIndex management table is generated on the RAM 102. Incidentally, atthis point, only sets of positional information of various types of datasuch as representative image data are merely acquired, and the varioustypes of data have not been read on the RAM 102 yet (Step 3203). Notethat, which AV Index file is the latest one can be judged from the filename. Then, sets of title character string data, attribute information,representative image data, and representative audio data of therespective entries are read out and stored in the AV Index managementtable (Step 3204).

Note that, when attribute information of a line having the sameentry-number as that of the line already existing in the AV Indexmanagement table is read out, the information is discarded. Uponcompletion of reading of available entry data, the file is closed (Step2306). Then, the field “previous” of the index link atom in thepreviously opened AV Index file is referred to in order to acquire thename of an AV Index file to be read next (Step 3207). Next, it isdetermined whether or not the previously opened AV Index file is an AVIndex to be last read (Step 3208). Specifically, if “NULL” indicatingthat there is no reference is specified to the name of the AV Index fileto be read next in the index link atom, it is determined that thepreviously opened AV Index file is the last AV Index. If that AV Indexis not the AV Index to be read last, a file having the name of the AVIndex file to be read next is opened (Step 3209), and Step 3203 and thesubsequent steps are performed.

As described above, in the Step 3201, reference to the AV Index fileexcept for the latest AV Index file makes it possible to easilyreproduce a previous snapshot (state) in the optical disk 106.

Variations

In the present embodiment, in updating entry data such as representativeimage data, all sets of entry data in an entry including the entry datato be updated are re-recorded. Taking FIG. 44 as an example, titlecharacter string data of SHRP0002.MOV recorded in a field 2255 isprimarily data which need not to be recorded since what is changed isonly representative image data. However, in the foregoing data format,the type of entry data to be changed cannot be specified, so thatchanging a certain type of entry data requires overwriting all types ofsets of entry data. As a method for solving this problem considered isto add the type of entry data to be changed, to attribute information.For example, for change of representative image data, “Status ofThumbnail” is set to “available”, and “Status of Intro music”, “Statusof Title” and others are set to “invalid”. On the occasion of reading,when the Status of Thumbnail is “available”, data is read out. When theStatus of Thumbnail is “invalid”, the existing data is used. Such anarrangement enables recording of only the entry data of the type to bechanged, and it is possible to reduce wasted recording space.

Further, in the present embodiment, entry deletion is carried out byaddition of an entry having the same entry-number and “invalid” statusof entry. Alternatively, entry deletion may be carried out by deletionof an AV Index file which manages an entry to be deleted. In this case,the number of entry managed in each AV Index file is limited to one.Further, entry deletion may be carried out by changing the file name ofthe AV Index file which manages an entry to be deleted, so as to make itineffective.

Third Embodiment

The following will describe third embodiment of the present inventionwith reference to FIGS. 48 through 52. The present embodiment and SecondEmbodiment are common in that duplicate recording of managementinformation is avoided, but the present embodiment is different fromSecond Embodiment in that management information and sets of entry dataare additionally written into one AV Index file.

Management Information Format

FIG. 48 illustrates a structure of an AV Index file in the presentembodiment with reference to FIG. 48. The AV Index file is realized bythe foregoing Fragmented movie. That is, at the head of the AV Indexfile, “Movie atom” that is management information of the entire file isprovided, and “Movie data atom” and “Movie fragment atom” are arrangedin an alternating manner. The Movie fragment atom has “Property track”,“Intro music track”, “Thumbnail track”, and “Title track” to manageattribute information, representative audio data, representative imagedata, and title character string data, respectively. Each Movie fragmentatom manages samples identical in number and time length for each track,to indicate that adjacent samples between tracks correspond to a commonentry.

For example, when Movie fragment atom 4103 manages m-number of entries,m-number of samples are managed respectively for attribute information,representative audio data, representative image data, and titlecharacter string data. The data corresponding to the sample is stored inMovie data atom 4102 that is Movie data atom which corresponds to theMovie fragment atom 4103.

Note that, formats of attribute information, representative audio data,representative image data, and title character string data are the sameas those in First Embodiment, so that descriptions thereof are omitted.

Flow of Entire Process

A flow from disk insertion to disk eject or power-off in the presentembodiment is the same as that in First Embodiment, so that descriptionsthereof are omitted. Here, it is assumed that an initial state beforethe process is started is such that on the optical disk 106, files havebeen recorded with a directory structure which is the same as that inFirst Embodiment, illustrated in FIG. 32(a), and directories on theoptical disk 106 are arranged as illustrated in FIG. 49. That is, AVfiles, SHRP0001.MOV, SHRP0002.MOV, and SHRP0003.MOV, are recorded in afield 4201, a field 4202, a field 4203, respectively. Further, an AVIndex file, AVIF0000.MOV, is recorded in a field 4204 in FIG. 49, at thehead of the field 4204, Movie atom of the AV Index file is recorded in afield 4211.

Further, as to SHRP0001.MOV, attribute information, title characterstring data, and representative image data are recorded in a field 4212,a field 4215, and a field 4218, respectively. As to SHRP0002.MOV,attribute information, title character string data, and representativeimage data are recorded in a field 4213, a field 4216, and a field 4219,respectively. As to SHRP0003.MOV, attribute information, title characterstring data, and representative image data are recorded in a field 4214,a field 4217, and a field 4220, respectively, and at the end, Moviefragment atom which manages the foregoing sets of entry data and Skipatom which will be described later are recorded in a field 4221 and afield 4222, respectively. Further, it is assumed that as a result of theindex screen display process described later, a table, illustrated inFIG. 37, for managing information regarding the AV Index file isstructured in the RAM 102.

Recording Process

Since recording process in the present embodiment is the same as that inFirst Embodiment, description thereof is omitted.

Entry Deletion Process

Since an entry deletion process in the present embodiment is the same asthat in First Embodiment, description thereof is omitted.

Entry Data Change Process

Since entry data change process in the present embodiment is the same asthat in First Embodiment, description thereof is omitted.

AV Index Recording Process

AV Index recording process in the present embodiment will be describedwith reference to FIG. 50. First, a process of unifying an AV Indexmanagement table on the RAM 102 is performed (Steps 4301 and 4302). Inaccordance with a result of the unifying process, Sample table isestablished (Step 4303). A specific procedure is the same as that inSecond Embodiment, so that description thereof is omitted. Next, Moviedata atom is recorded (Step 4304). Specifically, atom header isrecorded, and sets of attribute information, representative data,representative audio data, and title character string data of therespective entries are recorded. At the end, Movie fragment atom isrecorded based on contents of the foregoing Sample table (Step 4305).Upon completion of recording of the Movie fragment atom, the foregoingSkip atom is inserted for adjustment so that the bottom end of the fileis aligned with a boundary of the sectors. With this arrangement, the AVIndex file is made up of integer number of sectors. Note that, the Moviefragment atom and the Movie data atom may be recorded in the reverseorder. Further, for size adjustment, instead of the Skip atom, a set ofineffective data may be inserted immediately in front of the Moviefragment atom. In such a case, a field “size” in the atom header of theMovie data atom includes the amount of the ineffective data.

Thereafter, to cause the field subjected to recording at this time to beincluded in the existing AV Index file, this field is added as newextent to the FE which manages the AV Index file, and the FE isadditionally written into the disk. The size adjustment using the Skipatom is carried out to be consistent as QuickTime file even when theextent adding process is carried out.

Thus, the FE which is added the extent thereto and is additionallywritten into the disk is equivalent to “third data” recited in theclaims.

The following will specifically describe a recorded state on the opticaldisk 106 immediately after the above process is performed. It is assumedthat before the AV Index file recording process is started, there existsan AV Index management table having contents of FIG. 37 on the RAM 102.As a result of the AV Index file recording process, in the optical disk106, sets of data in fields 4230 through 4239 are additionally writtento the field 4242, as illustrated in FIG. 51(a). First, in a field 4230at the head of the field 4242, atom header of Movie data atom isrecorded. Sets of attribute information are recorded in fields 4231through 4233 and are respectively attribute information for nullifyingSHRP0001.MOV 4201, attribute information for replacing representativeimage data of SHRP0002.MOV 4202, and attribute information for newlyregistering SHRP0004.MOV 4241. To fields 4234 and 4235 respectivelyrecorded are sets of title character string data of SHRP0002.MOV 4202subjected to change of representative image and the newly registeredSHRP0004.MOV 4241.

To fields 4236 and 4237 respectively recorded are sets of representativeimage data of SHRP0002.MOV 4202 and SHRP0004.MOV 4241. To fields 4238and 4239 respectively recorded are Movie fragment atom and skip atom foraligning the bottom end of the file with a sector boundary. In thesituation that existing information and latest information regarding theAV Index file are recorded in fields 4204 and 4242, respectively, andthe field 4242 is added, as a subsequent extent, to the FE of the AVIndex file, fields of the AV Index file are read sequentially in thedirection from left to right in FIG. 51(b).

Index File Screen Display Process

The following will describe Index file screen display process in thepresent embodiment with reference to FIG. 52. First, the AV Index fileis opened (Step 4401), and Movie atom is read (Step 4402). Next, fieldsfollowing the Movie atom are read, and if the read field is the bottomof the file (Step 4403), the index screen is displayed (Step 4404) tocomplete the process. If the read field is not the bottom of the file,it is judged whether or not the read field is the Movie fragment atom(Step 4405). If the read field is the Movie fragment atom, the Moviefragment atom is read (Step 4406). In accordance with informationobtained from the Movie fragment atom, Movie data atom, i.e. entry datasuch as attribute information, is read (Step 4407). In the Step 4405,when the read field is atom except for the Movie fragment atom, fieldsare skipped until the Movie fragment atom is read (Step 4408).

Variations

The present embodiment, as with Second Embodiment, makes it possible toreduce wasted recording space by recording type information of entrydata to be changed illustrated in FIG. 47.

Further, in the present embodiment, entry deletion is carried out byadditionally writing an entry having the same entry-number.Alternatively, entry deletion may be carried out by deleting, from theFE of the AV Index file, an extent corresponding to Fragmented Moviewhich manages an entry to be deleted. Note that, it is necessary toignore discontinuous sequence-numbers.

Still further, in the present embodiment, reading of the file startsfrom the head of the file, so that a time to access to recently recordedsets of entry data tends to be longer. In order to avoid this problem,the FE of the AV Index file may be set so that sets of entry data arearranged in an order such that a newly recorded entry data comes first.In this case, needless to say, as has been described in the First andSecond Embodiments, duplicate recording of only entry data having aparticular attribute may be carried out for high-speed access to entrydata.

Fourth Embodiment

The following will describe fourth embodiment of the present inventionwith reference to FIGS. 53(a) through 59(b). The present embodiment issimilar to First Embodiment; however, the present embodiment isdifferent from First Embodiment in that recorded data including Movieatom is reused wherever possible by manipulation of the FE regarding theAV Index file. The following description focuses on AV Index file updateprocess.

A management information format of the present embodiment is the same asthat of First Embodiment, so that description thereof is omitted.

AV Index File Update Process (in the Case when the Variation in theAmount of Data in Movie Atom is an Integer Multiple of Sector)

First, referring to FIGS. 53(a), 53(b), and 54, the following willdescribe AV Index file update process in the case when the variation insize of the Movie atom is only an integer multiple of sector (includingthe case when the size of the Movie atom does not change by update ofthe AV Index file).

First, the following will describe FIG. 53(a) illustrating a datastructure of an AV Index file before being updated. The AV Index file ismade up of Movie atom 5101, atom header 5102, and Movie data atomincluding attribute information 5103 and others. Here, it is consideredto change the contents of the attribute information 5103 and the amountof data thereof in the Movie data atom. In the present case, the size ofthe Movie data atom changes, so that the need for rewriting of a field“size” of the atom header 5102 arises. Further, the size of theattribute information 5103 changes, so that there arises the need forrewriting of amount-of-data information (Sample size atom) of theattribute information 5103 and sample positional information (Chunkoffset atom) corresponding to data following the amount-of-datainformation. That is, there arises the need for partial rewriting of theMovie atom 5101. In the present case, a part which requires to berewritten is termed “change-required part 5104”. Note that, thisrewriting causes no change in the number of samples, which generallycauses no increase or decrease in the amount of data of Sample tableatom.

It is assumed that the AV Index file illustrated in FIG. 53(a) isrecorded in a field 5221 on the optical disk 106 as illustrated in FIG.54, and the attribute information 5103, the atom header 5102, and thechange-required part 5104 are provided on the corresponding sectors onthe disk. Note that, data 5201 and data 5202 are data on the left sideand data on the right side of the change-required part 5104,respectively, in a sector string storing the change-required part.Similarly, data 5203 and data 5204 are data on the left side and data onthe right side of the atom header 5102, respectively. Further, data 5205and data 5206 are data on the left side and data on the right side ofthe attribute information 5103, respectively.

According to change process, post-change attribute information 5113,post-change atom header 5112, and change result 5114 of thechange-required part 5104 are recorded in the following manner: First,as to the post-change attribute information 5113, the data 5205, theattribute information 5113, padding 5207, and the data 5206 are recordedin this order. The padding 5207 is invalid data for making the amount ofaggregate data of the data 5205, the attribute information 5113, thepadding 5207, and the data 5206, equal to an integer multiple of asector size.

Note that, the padding 5207 is equivalent to “ineffective data” recitedin the claims.

Next, as to the post-change atom header 5112, the data 5203, the atomheader 5112, and the data 5204 are recorded in this order. For the atomheader 5112, there occurs no change in the amount of data, so that thereis no need to use such a padding that has been described in associationwith recording of the attribute information.

Next, as to the change result 5114, the data 5207, the change result5114, and the data 5202 are recorded in this order. As mentioned above,there occurs no change in the amount of data, so that there is no needto use the padding.

At the end, the FE of the AV Index file is structured and additionallywritten so that R1, R10, R3, R9, R5, R6, and R8 in FIG. 54 are read inthis order.

Such a FE restructured and additionally written is equivalent to “thirddata” recited in the claims.

According to the above-mentioned process, the AV Index file is rewrittenas illustrated in FIG. 53(b). Note that, here, the attribute informationis to be changed. However, in the case of changing other entry data suchas thumbnail, the AV Index file is rewritten in the same manner.

The foregoing AV Index file update process minimizes wasted recordingspace caused by the change.

AV Index File Update Process (in the Case when the Variation in theAmount of Data in the Movie Atom is not an Integer Multiple of Sector)

Next, referring to FIGS. 55(a), 55(b), and 56, the following willdescribe AV Index file update process in the case when the variation insize of the Movie atom is variation except for an integer multiple ofsector.

FIG. 55(a) illustrates a data structure of the AV Index file beforebeing updated. This data structure is the same as that in FIG. 53(a), sothat description thereof is omitted. Now, it is considered that entrydata such as attribute information is added to the AV Index file. Theaddition increases the number of samples managed by the Movie atom 5101and increases the number of entries in Chunk offset atom, i.e. causesadditional management information. With this, there arises the need forupdating the field “size” in the atom header of the high-order atom.Further, addition of entry data increases the amount of data in theMovie data atom, so that there arises the need for updating the field“size” of the atom header in the Movie data atom.

It is assumed that the AV Index file illustrated in FIG. 55(a) isrecorded in a field 5221 on the optical disk 106 as illustrated in FIG.56, and an insertion position of the additional management information5303, caused by increase in the number of entries in the Chunk offsetatom, is a data addition point 5301. Note that, the atom header of theMovie data atom and others in which there occurs no change in the amountof data are the same as those in FIG. 54, so that descriptions thereofare omitted. Note that, data 5311 and data 5313 are data on the leftside and data on the right side of the data addition point 5301,respectively, in a sector including the data addition point 5301.

According to change process, the data 5311, the data 5313, theadditional management information 5303, and the additional entry data5302 are recorded in the following manner: First, the data 5311, theadditional management information 5303, the data 5313, and data 5314 arerecorded in this order from the top sector of the sectors. Also, theadditional entry data 5302 is recorded in another sector string. Notethat, the data 5314 is ineffective data that exists from the end of thedata 5313 to the end of the sector. At the end, as illustrated in FIG.57(a), the FE of the AV Index file is structured and additionallywritten in the order of R11, R14, R13, and R15. In this case, the data5314 is ineffective data, so that when this AV Index file is interpretedfrom the top thereof, the AV Index file cannot be interpreted correctly.In order to avoid the incorrect interpretation, information fornullifying such ineffective data is recorded on the optical disk 106.Specifically, a file “SKIP0000.DAT” is generated to record therein theaddress and the number of bytes of the ineffective data in the AV Indexfile.

On the occasion of reading the AV Index, the SKIP0000.DAT is read outimmediately before the reading, and in accordance with information ofthe SKIP0000.DAT, the AV Index file is interpreted.

The above-mentioned update process minimizes duplicate recording of datain the Movie atom, caused by update of the AV Index file.

Variations

In the present embodiment, sets of data including ineffective data arecombined into one file. Alternatively, the sets of data may be managedby a plurality of files, i.e. one partial AV Index file 5321 and onepartial AV Index file 5324. The partial AV Index file 5321 manages R11,the data 5311, the additional management information 5303, and the data5313. The partial AV Index file 5324 manages R13 and the additionalentry data 5302. Successive reading of the partial AV Index file 5321and the partial AV Index file 5324 realizes reconstruction of the AVIndex file on the RAM 102. As a method of managing the order of readinga plurality of files considered is the following method. For example, itcan be considered that as for files making up the latest AV Index file,the files are assigned file names, like AVIF0001.MOS and AVIF0002.MOS,indicating the order in which the files are read. Here, the extension“MOS” indicates a divided file. Also, it can be considered that a filerecording the order in which the files are read is generated and thegenerated file is always referred to when the AV Index is read.

Further, it can be considered that additional data including theadditional management information 5303 is recorded, in another file,together with information which manages an addition position and thegenerated file is always referred to when the AV Index is read.

Further, in the present embodiment, in the case where the data size ofthe additional management information is less than an integer multipleof sector, padding is inserted. For the padding, an atom in theQuickTime file format may be used. This is described with reference toFIG. 58. Note that, components having the same functions as thosedescribed above are given the same reference numerals and explanationsthereof are omitted here. On the occasion of update process, first, apadding insertable point, specifically, a boundary between atoms issearched on the right side of he data addition point 5301. The pointthat is found first is a padding insertable point 5320. Further, it isdefined that data from the data addition point 5301 to the paddinginsertable point 5320 is data 5321, and data from the padding insertablepoint 5320 to the first sector boundary is data 5322.

From the foregoing sets of data, the data 5311, the additionalmanagement information 5303, the data 5321, padding 5323, and the data5322 are recorded in this order. Here, the padding 5323 is inserted sothat the foregoing sets of data becomes the amount of data that is aninteger multiple of sector, and what is used for the padding 5323 is anineffective atom ignored in reproduction, like the foregoing skip atom.At the end, the FE of the AV Index file is structured and additionallywritten so that R11, R23, R22, R16 are read in this order from the AVIndex file. Thus, to add data that is not an integer multiple of sector,insertion of an atom for size adjustment into the boundary between atomsreduces additional writing of data, and in addition, enablesinterpretation of the AV Index file without reference to other files.

Still further, the present embodiment assumes that the update processcauses increase or decrease in atom size of the Movie atom.Alternatively, it can be considered that for an atom which increases ordecreases its size (e.g. edit atom and sample atom), a space ofsufficient size is held at the initial recording of the AV Index file,and to an unassigned field, as illustrated in FIG. 59(a), an ineffectiveatom (here termed “null atom”) which is ignored at the time ofreproduction is recorded. For example, when addition of sampleinformation increases the amount of data of Chunk offset atom from chunkoffset atom 5401 to chunk offset atom 5403 in FIG. 59(a), the head ofthe null atom following the Chunk offset atom is shifted backward of thefile for reduction of null atom size, which makes it possible to preventchange of the atom header of the high-order atom and change of Chunkoffset caused by movement of the Movie data atom, i.e. increase ofadditionally rewritten data. Such an arrangement eliminates the need fordivision of the AV Index file and additional information forinterpreting the contents of the AV Index file. Further, a head 5405 ofan atom whose size increases or decreases and an end 5406 of null atomare aligned with sector boundaries, whereby it is possible to simplifythe process.

Further, instead of insertion of ineffective atom into an unassignedfield at the time of initial recording of the AV Index file, asufficient number of empty samples may be registered, as illustrated inFIG. 59(b). In the case of FIG. 59(b), “1000” is recorded to number ofentries 5412, a field managing the number of entries in chunk offsetatom 5411, and 1000 entries are registered between entry data 5413 andentry data 5414. In the present case, in association with entry additionto the AV Index file, information regarding actual data is registered tothe empty sample. As a method for indicating that the sample is empty,it can be considered to set codec information of the sample to invalidinformation. Alternatively, field may be reserved by managing an atomsize in the atom header so as to be larger than an atom sizecorresponding to the number of entries actually managed. Further, headand bottom ends of the chunk offset atom are aligned with sectorboundaries, whereby it is possible to simplify the process. Such anarrangement eliminates the need for division of the AV Index file andadditional information for interpreting the contents of the AV Indexfile. Needless to say, these methods are also applicable to edit listatom, for example.

Also, needless to say, the update process described in the presentembodiment is applicable to not only the AV Index file but also the AVfile.

Supplemental Descriptions Through All of the Embodiments

Note that, in the foregoing embodiments, DVD-R is used as a recordingmedium. However, needless to say, the present invention is applicable toa recording medium except for DVD-R, provided that the recording mediumis a write-once recording medium. In addition, apart from the write-oncerecording medium, the present invention is also applicable to arecording medium which is put limitations on the number of times it isrewritten, e.g. flash ROM. Therefore, in the present embodiments, a unitfor data management is sector. However, in the case where the presentinvention is applied to different recording media, the sector isreplaced by data management/recording units of the respective recordingmedia.

Note that, in the foregoing embodiments, UDF is used for a file system.However, a file system of the present invention is not limited to theUDF.

Further, in the foregoing embodiments, AV data such as audio data andvideo data is used as data. However, data of the present invention isnot limited to the AV data.

Note that, in the foregoing embodiments, QuickTime file format is usedas a file format. However, a file format of the present invention is notlimited to the QuickTime file format.

As described above, according to the present invention, at the time ofrecording of additionally written data, information which managesavailability/invalidity of an existing data is recorded, whereby thereuse of the existing data is possible, thus reducing wasted recordingspace.

Further, according to the present invention, at the time of recording ofadditionally written data, the same data as the existing data isrecorded depending on the attribute of the existing data, whereby it ispossible to read data having a particular attribute at a high speed,thus improving responses to the user.

Note that, specific manners or embodiments implemented in the best modefor carrying out the invention only show technical features of thepresent invention and are not intended to limit the scope of theinvention. Variations can be effected within the spirit of the presentinvention and the scope of the following claims.

INDUSTRIAL APPLICABILITY

The present invention relates to a data recording method, data recordingdevice, data recording medium, data reproduction method, and datareproduction device, concerning recording video or audio data to arandom-access storage medium such as a hard disk and an optical disk. Inwrite-once media, there occurs wasted recording space at the time ofupdate of an index file for AV file management. In view of this, a newindex file is generated at the time of update, and thumbnail image datain an existing index file is referred to, whereby the wasted space isreduced, At the same time, attribute information is stored in the newindex file, whereby access to minimum information required can befaster.

1-2. (canceled)
 3. A data recording method, wherein: a set of firstdata, a set of second data, and a set of third data are recorded on arecording medium, the set of first data includes sets of fourth data,the set of third data includes sets of information for referring to therespective sets of fourth data, the set of second data is allowed toinclude a set of data which is same as the set of fourth data, andwhether or not the set of second data includes the same data as the setof fourth data is determined in accordance with attribute of the set offourth data.
 4. The data recording method according to claim 3, wherein:whether or not the set of second data includes the same data as the setof fourth data is determined in accordance with amount of the set offourth data.
 5. The data recording method according to claim 3, wherein:whether or not the set of second data includes the same data as the setof fourth data is determined in accordance with hierarchical informationof the set of fourth data.
 6. The data recording method according toclaim 3, wherein: whether or not the set of second data includes thesame data as the set of fourth data is determined in accordance withpriority of the set of fourth data.
 7. The data recording methodaccording to claim 3, wherein: whether or not the set of second dataincludes the same data as the set of fourth data is determined inaccordance with a time at which data associated with the set of fourthdata has been reproduced.
 8. The data recording method according toclaim 3, wherein: the attribute of the set of fourth data is recorded onthe recording medium.
 9. (canceled)
 10. A data recording method,wherein: a set of first data, a set of second data, and a set of thirddata are recorded on a recording medium, the set of first data includessets of fourth data, the set of third data includes sets of informationfor referring to the respective sets of fourth data, the set of seconddata includes a set of data which is same as the set of fourth data, andto store the set of second data including the set of fourth data in aninteger number of recording units, a set of ineffective data isinserted.
 11. The data recording method according to claim 10, wherein:a set of data for nullifying the set of ineffective data is recorded onthe recording medium.
 12. The data recording method according to claim10, wherein: an insertion position of the set of ineffective data is aposition at which the set of ineffective data can be inserted. 13-15.(canceled)
 16. A data recording method, wherein: a set of first data, aset of second data, and a set of third data are recorded on a recordingmedium, the set of first data includes sets of fourth data, the set ofthird data includes sets of information for referring to the respectivesets of fourth data, the set of first data and the set of second dataare managed as different files, and relevant information between thefiles is recorded on the recording medium.
 17. The data recording methodaccording to claim 16, wherein: the relevant information is representedby a name of the file.
 18. The data recording method according to claim16, wherein: the set of third data is a name of a file including the setof fourth data being available and is positional information inside thefile.
 19. The data recording method according to claim 16, wherein: theset of third data is information which nullifies the set of fourth data.20. The data recording method according to claim 16, wherein: the set ofthird data and the set of fourth data are recorded in different files.21. The data recording method according to claim 3, wherein: the set offirst data and the set of second data are managed as one file.
 22. Adata recording method, wherein: a set of first data, a set of seconddata, and a set of third data are recorded on a recording medium, theset of first data includes sets of fourth data, the set of third dataincludes sets of information for referring to the respective sets offourth data, the set of first data and the set of second data aremanaged as one file, and the set of fourth data is recorded in such amanner that its head position is fit to a boundary of recording units.23. A data recording method, wherein: a set of first data, a set ofsecond data, and a set of third data are recorded on a recording medium,the set of first data includes sets of fourth data, the set of thirddata includes sets of information for referring to the respective setsof fourth data, the set of first data and the set of second data aremanaged as one file, and the set of second data is made up of an integernumber of recording units.
 24. The data recording method according toclaim 21, wherein: the set of third data is positional information ofthe set of fourth data being available, inside the file.
 25. The datarecording method according to claim 21, wherein: the set of third datais information which nullifies the set of fourth data.
 26. The datarecording method according to claim 3, wherein: the set of third data isrecorded close to an additional writing end position on the recordingmedium.
 27. The data recording method according to claim 3, wherein:sets of fifth data are recorded on the recording medium, and each of thesets of fourth data is information regarding the set of fifth data. 28.The data recording method according to claim 27, wherein: theinformation regarding the set of fifth data is at least one ofrepresentative image data, representative audio data, title data, andattribute data of the set of fifth data.
 29. The data recording methodaccording to claim 3, wherein: the recording medium is a write-oncemedium.
 30. The data recording method according to claim 3, wherein: theset of third data is recorded close to information indicating a lastadditional writing end position.
 31. The data recording method accordingto claim 3, wherein: the set of second data is additional data of theset of first data.
 32. A data recording device, wherein: included isrecording means which records a set of first data, a set of second data,and a set of third data on a recording medium, the set of first dataincludes sets of fourth data, the set of third data includes sets ofinformation for referring to the respective sets of fourth data, the setof second data is allowed to include a set of data which is same as theset of fourth data, and whether or not the set of second data includesthe same data as the set of fourth data is determined in accordance withattribute of the set of fourth data.
 33. A data recording medium,wherein: a set of first data, a set of second data, and a set of thirddata are recorded thereon, the set of first data includes sets of fourthdata, the set of third data includes sets of information for referringto the respective sets of fourth data, the set of second data is allowedto include a set of data which is same as the set of fourth data, andwhether or not the set of second data includes the same data as the setof fourth data is determined in accordance with attribute of the set offourth data. 34-35. (canceled)
 36. A data recording method for, by meansof a data recording device, changing records in a data recording mediumincluding (a) sets of main data and (b) sets of index data each of whichincludes sets of index information regarding the respective sets of maindata, recorded thereon, the data recording method comprising the stepsof: index data generating means of the data recording device, generatingnew index data reflecting records changed; and recording means of thedata recording device, recording the generated new index data on thedata recording medium, the new index data including: sets of referenceinformation for referring to part of sets of index information which areincluded in old index data and of which changes are not needed, the oldindex data having been already recorded on the data recording medium;and sets of index information which are same as the other part of setsof index information which are included in the old index data and ofwhich changes are not needed, the old index data having been alreadyrecorded on the data recording medium, wherein: whether or not the newindex data includes the same index information as the set of indexinformation included in the old index data is determined in accordancewith attribute of the set of index information.
 37. (canceled)
 38. Adata recording device which changes records in a data recording mediumincluding (a) sets of main data and (b) sets of index data each of whichincludes sets of index information regarding the respective sets of maindata, recorded thereon, the data recording device comprising: index datagenerating means which, at the time of changing the records in the datarecording medium, generates new index data reflecting the recordschanged; and recording means which records the generated new index dataon the data recording medium, the index data generating means causingthe new index data to include: sets of reference information forreferring to part of sets of index information which are included in oldindex data and of which changes are not needed, the old index datahaving been already recorded on the data recording medium; and sets ofindex information which are same as the other part of sets of indexinformation which are included in the old index data and of whichchanges are not needed, the old index data having been already recordedon the data recording medium, wherein: whether or not the new index dataincludes the same index information as the set of index informationincluded in the old index data is determined in accordance withattribute of the set of index information.
 39. (canceled)
 40. A datarecording medium including (a) sets of main data and (b) sets of indexdata each of which includes sets of index information regarding therespective sets of main data, recorded thereon, the data recordingmedium comprising: old index data being recorded before records arechanged; and new index data being recorded after records are changed,the new index data including: sets of reference information forreferring to part of sets of index information which are included in theold index data and of which changes are not needed even after therecords are changed; and sets of index information which are same as theother part of sets of index information included in the old index data,wherein: whether or not the new index data includes the same indexinformation as the set of index information included in the old indexdata is determined in accordance with attribute of the set of indexinformation.
 41. (canceled)
 42. A data reproduction method for, by meansof a data reproduction device, reproducing records in a data recordingmedium including (a) sets of main data and (b) sets of index data eachof which includes sets of index information regarding the respectivesets of main data, recorded thereon, the data recording medium including(c) old index data being recorded before the records are changed and (d)new index data being recorded after the records are changed, the newindex data including: sets of reference information for referring topart of sets of index information which are included in the old indexdata and of which changes are not needed even after the records arechanged; and sets of index information which are same as the other partof sets of index information included in the old index data, wherein:whether or not the new index data includes the same index information asthe set of index information included in the old index data isdetermined in accordance with attribute of the set of index information,the data reproduction method comprising the steps of: reproducing meansof the data reproduction device, acquiring the sets of index informationfrom the old index data in accordance with the sets of referenceinformation included in the new index data; reproducing means of thedata reproduction device, acquiring the sets of index informationincluded in the new index data.
 43. (canceled)
 44. A data reproductiondevice which reproduces records in a data recording medium including (a)sets of main data and (b) sets of index data each of which includes setsof index information regarding the respective sets of main data,recorded thereon, the data recording medium including (c) old index databeing recorded before the records are changed and (d) new index databeing recorded after the records are changed, the new index dataincluding: sets of reference information for referring to part of setsof index information which are included in the old index data and ofwhich changes are not needed even after the records are changed; andsets of index information which are same as the other part of sets ofindex information included in the old index data, wherein: whether ornot the new index data includes the same index information as the set ofindex information included in the old index data is determined inaccordance with attribute of the set of index information, the datareproduction device comprising: reproducing means which, in reproducingthe records in the data recording medium, acquires the sets of indexinformation from the old index data in accordance with the sets ofreference information included in the new index data, and acquires thesets of index information included in the new index data. 45-50.(canceled)
 51. The data recording method according to claim 10, wherein:the set of third data is recorded close to an additional writing endposition on the recording medium.
 52. The data recording methodaccording to claim 16, wherein: the set of third data is recorded closeto an additional writing end position on the recording medium.
 53. Thedata recording method according to claim 22, wherein: the set of thirddata is recorded close to an additional writing end position on therecording medium.
 54. The data recording method according to claim 23,wherein: the set of third data is recorded close to an additionalwriting end position on the recording medium.
 55. The data recordingmethod according to claim 10, wherein: sets of fifth data are recordedon the recording medium, and each of the sets of fourth data isinformation regarding the set of fifth data.
 56. The data recordingmethod according to claim 16, wherein: sets of fifth data are recordedon the recording medium, and each of the sets of fourth data isinformation regarding the set of fifth data.
 57. The data recordingmethod according to claim 22, wherein: sets of fifth data are recordedon the recording medium, and each of the sets of fourth data isinformation regarding the set of fifth data.
 58. The data recordingmethod according to claim 23, wherein: sets of fifth data are recordedon the recording medium, and each of the sets of fourth data isinformation regarding the set of fifth data.
 59. The data recordingmethod according to claim 10, wherein: the recording medium is awrite-once medium.
 60. The data recording method according to claim 16,wherein: the recording medium is a write-once medium.
 61. The datarecording method according to claim 22, wherein: the recording medium isa write-once medium.
 62. The data recording method according to claim23, wherein: the recording medium is a write-once medium.
 63. The datarecording method according to claim 10, wherein: the set of third datais recorded close to information indicating a last additional writingend position.
 64. The data recording method according to claim 16,wherein: the set of third data is recorded close to informationindicating a last additional writing end position.
 65. The datarecording method according to claim 22, wherein: the set of third datais recorded close to information indicating a last additional writingend position.
 66. The data recording method according to claim 23,wherein: the set of third data is recorded close to informationindicating a last additional writing end position.
 67. The datarecording method according to claim 10, wherein: the set of second datais additional data of the set of first data.
 68. The data recordingmethod according to claim 16, wherein: the set of second data isadditional data of the set of first data.
 69. The data recording methodaccording to claim 22, wherein: the set of second data is additionaldata of the set of first data.
 70. The data recording method accordingto claim 23, wherein: the set of second data is additional data of theset of first data.
 71. The data recording method according to claim 16,wherein: the set of second data includes a set of data which is same asthe set of fourth data, and the set of first data includes a front and arear of the set of fourth data, managed as different files, and relevantinformation between the files is recorded on the recording medium. 72.The data recording method according to claim 16, wherein: the set offirst data and the set of second data are recorded in different files,and reading control information of the files is recorded on therecording medium.